Final Chapter 10: Genetic Disorders & Prenatal Screening

Question 1

A nurse is educating a pregnant patient about the purpose of an ultrasound in the first trimester. Which statement by the patient indicates understanding?

A) “The ultrasound can determine my baby’s gender at this stage.”
B) “It will confirm the presence of a fetal heartbeat and gestational age.”
C) “This test will screen for gestational diabetes.”
D) “The ultrasound will check my cervix for dilation.”

Answer 1

B) “It will confirm the presence of a fetal heartbeat and gestational age.”

Rationale: First-trimester ultrasound confirms pregnancy, detects a fetal heartbeat, estimates gestational age, and rules out ectopic pregnancy. Fetal gender is typically determined after 16-20 weeks.

Question 2

A patient at 32 weeks gestation is scheduled for a biophysical profile (BPP) via ultrasound. What does this test assess?

A) Placental maturity and fetal position
B) Fetal heart rate, movement, tone, breathing, and amniotic fluid volume
C) Cervical dilation and risk for preterm labor
D) The presence of fetal anomalies

Answer 2

B) Fetal heart rate, movement, tone, breathing, and amniotic fluid volume

Rationale: A biophysical profile (BPP) is a comprehensive fetal assessment that evaluates fetal well-being through ultrasound and a nonstress test (NST). A score of 8-10 is reassuring, while a low score indicates fetal distress.

Question 3

A nurse is preparing a patient for a transabdominal ultrasound at 20 weeks gestation. What pre-procedure instruction should be given?

A) “Drink several glasses of water before the exam and do not urinate.”
B) “You need to empty your bladder completely before the test.”
C) “Avoid eating or drinking for 8 hours before the procedure.”
D) “This test requires an intravenous contrast injection.”

Answer 3

A) “Drink several glasses of water before the exam and do not urinate.”

Rationale: A full bladder improves visualization of pelvic structures during transabdominal ultrasound. In contrast, a transvaginal ultrasound requires an empty bladder.

Question 4

A pregnant patient asks about the risks of ultrasound screening. Which response by the nurse is correct?

A) “Ultrasounds expose the baby to radiation, so they should be limited.”
B) “Ultrasounds may cause birth defects if done too frequently.”
C) “You will need sedation during the procedure.”
D) “Ultrasound is noninvasive and does not pose known risks to you or your baby.”

Answer 4

D) “Ultrasound is noninvasive and does not pose known risks to you or your baby.”

Rationale: Ultrasound uses sound waves (not radiation) and is considered safe during pregnancy. It does not cause birth defects and does not require sedation.

Question 5

A patient is undergoing a nuchal translucency ultrasound at 12 weeks gestation. What condition is this test primarily screening for?

A) Spina bifida
B) Down syndrome and chromosomal abnormalities
C) Fetal lung maturity
D) Placental abruption

Answer 5

B) Down syndrome and chromosomal abnormalities

Rationale: Nuchal translucency ultrasound measures the fluid at the back of the fetal neck. Increased thickness may indicate trisomy 21 (Down syndrome) or other chromosomal abnormalities. It is typically performed between 11-14 weeks.

Question 6

A nurse is assisting with a transvaginal ultrasound for a first-trimester patient. Which action is appropriate?

A) Ask the patient to empty their bladder before the procedure.
B) Ensure the patient has a full bladder for better visualization.
C) Position the patient in a prone position.
D) Place the ultrasound probe directly on the patient’s abdomen.

Answer 6

A) Ask the patient to empty their bladder before the procedure.

Rationale: Unlike transabdominal ultrasound, transvaginal ultrasound provides better visualization without a full bladder. The patient is positioned supine with knees bent.

Question 7

A nurse is reviewing ultrasound results for a patient at 36 weeks gestation. Which finding is most concerning?

A) Amniotic fluid index (AFI) of 8 cm
B) Fetal heart rate of 140 bpm
C) Placenta previa covering the cervix
D) Fetal presentation in cephalic position

Answer 7

C) Placenta previa covering the cervix

Rationale: Placenta previa at 36 weeks increases the risk of hemorrhage and may require a C-section. The other findings are normal for a term pregnancy.

Question 8

A 24-week pregnant patient is undergoing an ultrasound for fetal growth assessment. Which measurement is most commonly used?

A) Cervical length
B) Amniotic fluid index
C) Biparietal diameter and femur length
D) Endometrial thickness

Answer 8

C) Biparietal diameter and femur length

Rationale: Biparietal diameter (BPD), head circumference, femur length, and abdominal circumference are used to assess fetal growth and estimated gestational age in the second and third trimesters.

Question 9

A nurse is explaining the doppler ultrasound portion of a biophysical profile (BPP). What is the purpose of this test?

A) To measure amniotic fluid levels
B) To assess fetal breathing movements
C) To evaluate blood flow through the umbilical cord and placenta
D) To determine fetal weight

Answer 9

C) To evaluate blood flow through the umbilical cord and placenta

Rationale: Doppler ultrasound assesses fetal circulation and placental function. It is commonly used in high-risk pregnancies (e.g., IUGR, preeclampsia).

Question 10

A nurse is reviewing a patient’s ultrasound report at 28 weeks gestation. The amniotic fluid index (AFI) is 4 cm. What condition should the nurse suspect?

A) Oligohydramnios
B) Polyhydramnios
C) Normal findings
D) Hydatidiform mole

Answer 10

A) Oligohydramnios

Rationale: An AFI <5 cm indicates oligohydramnios, which is associated with fetal renal abnormalities, placental insufficiency, and fetal distress. Polyhydramnios is diagnosed if AFI > 25 cm.

Question 11

What is the probability that an affected individual with an autosomal dominant disorder will pass the disorder on to their child?

A) 25%
B) 50%
C) 75%
D) 100%

Answer 11

B) 50%

Rationale: In autosomal dominant inheritance, an affected individual with one affected parent has a 50% chance of passing the disorder on to their child. This is because the affected parent has one dominant allele for the disorder, which can be transmitted to the offspring.

Question 12

Which characteristics are true for autosomal dominant inheritance?(SATA)

A) Affected individuals always have two affected parents
B) Males and females are equally affected
C) The disorder can skip generations
D) The probability of passing the disorder is 50%

Answer 12

B) Males and females are equally affected
D) The probability of passing the disorder is 50%

Rationale: In autosomal dominant inheritance, males and females are equally affected, and an affected individual has a 50% chance of passing the disorder on to their offspring. It is not necessary for both parents to be affected, and the disorder generally does not skip generations.

Question 13

Which nervous system disorder is commonly associated with autosomal dominant inheritance?

A) Cystic fibrosis
B) Sickle cell anemia
C) Phenylketonuria (PKU)
D) Huntington’s Disease

Answer 13

D) Huntington’s Disease

Rationale: Huntington’s Disease is a common autosomal dominant disorder affecting the nervous system, characterized by abnormal involuntary movements and progressive dementia.

Question 14

What are the primary characteristics of polycystic kidney disease in autosomal dominant inheritance?

A) Small, functional cysts throughout the liver
B) Grape-like clusters of fluid-filled cysts in the kidney
C) Abnormal liver function
D) Increased cognitive function

Answer 14

B) Grape-like clusters of fluid-filled cysts in the kidney

Rationale: Polycystic kidney disease, an autosomal dominant disorder, is characterized by grape-like clusters of fluid-filled cysts in the kidney that replace functioning renal tissue, leading to renal impairment.

Question 15

Which disorders are examples of autosomal dominant inheritance? (SATA)

A) Huntington’s Disease
B) Polycystic kidney disease
C) Cystic fibrosis
D) Tay-Sachs disease

Answer 15

A) Huntington’s Disease
B) Polycystic kidney disease

Rationale: Examples of autosomal dominant inheritance include Huntington’s Disease and polycystic kidney disease. Cystic fibrosis and Tay-Sachs disease are examples of autosomal recessive disorders.

Question 16

How does autosomal dominant inheritance affect males and females?

A) Only males are affected
B) Only females are affected
C) Males and females are equally affected
D) It varies depending on environmental factors

Answer 16

C) Males and females are equally affected

Rationale: In autosomal dominant inheritance, both males and females are equally affected, as the disorder is inherited regardless of sex because the defective gene is located on an autosome (nonsex chromosome).

Question 17

What is the main characteristic of autosomal dominant inheritance disorders?

A) Both alleles must be abnormal for the disorder to be expressed
B) The disorder skips generations
C) Only males are affected
D) A single gene in the heterozygous state is capable of producing the phenotype

Answer 17

D) A single gene in the heterozygous state is capable of producing the phenotype

Rationale: Autosomal dominant inheritance disorders occur when a single abnormal or mutant gene in the heterozygous state overshadows the normal gene, resulting in the expression of the disorder’s phenotype.

Question 18

Which statements are true regarding autosomal dominant inheritance disorders?

A) The affected individual has a 50% chance of passing the abnormal gene to each child
B) Males and females are equally affected
C) The disorder can be passed from an affected male to his son
D) Phenotypically normal family members do not transmit the condition

Answer 18

all of the choices are correct

Rationale: In autosomal dominant inheritance, affected individuals have a 50% chance of passing the abnormal gene to each child. Males and females are equally affected, and an affected male can pass the disorder to his son. Phenotypically normal family members do not transmit the condition.

Question 19

Why is male-to-male transmission important in distinguishing autosomal dominant inheritance from X-linked inheritance?

A) Because only autosomal recessive disorders show male-to-male transmission

B) Because autosomal dominant disorders do not affect females

C) Because X-linked inheritance does not exhibit male-to-male transmission

D) Because autosomal dominant disorders are inherited from the mother only

Answer 19

C) Because X-linked inheritance does not exhibit male-to-male transmission

Rationale: Male-to-male transmission is important in distinguishing autosomal dominant inheritance from X-linked inheritance because X-linked inheritance does not exhibit male-to-male transmission, as males inherit the X chromosome from their mothers.

Question 20

What is the significance of varying degrees of presentation among individuals in a family with an autosomal dominant disorder?

A) It indicates that only some family members carry the gene

B) It means that all family members will have the same severity of the disorder

C) It means a parent with a mild form could have a child with a more severe form

D) It indicates the disorder is not inherited

Answer 20

C) It means a parent with a mild form could have a child with a more severe form

Rationale: Varying degrees of presentation among individuals in a family with an autosomal dominant disorder indicate that a parent with a mild form of the disorder could have a child with a more severe form, highlighting the variable expressivity of the disorder.

Question 21

Which disorders follow an autosomal dominant pattern of inheritance?

A) Neurofibromatosis
B) Huntington disease
C) Achondroplasia
D) Polycystic kidney disease

Answer 21

all of the choices are correct

Rationale: Common genetic disorders that follow an autosomal dominant pattern of inheritance include neurofibromatosis, Huntington disease, achondroplasia, and polycystic kidney disease.

Question 22

Which disorder is characterized by the growth of multiple, bilateral, grape-like clusters of fluid-filled cysts in the kidneys?

A) Huntington disease
B) Neurofibromatosis
C) Achondroplasia
D) Polycystic kidney disease

Answer 22

D) Polycystic kidney disease

Rationale: Polycystic kidney disease is characterized by the growth of multiple, bilateral, grape-like clusters of fluid-filled cysts in the kidneys that eventually compress and replace functioning renal tissue.

Question 23

How is an autosomal dominant disorder inherited if one parent is affected?

A) There is a 25% chance the child will be affected
B) There is a 50% chance the child will be affected
C) There is a 75% chance the child will be affected
D) The disorder skips a generation

Answer 23

B) There is a 50% chance the child will be affected

Rationale: If one parent is affected by an autosomal dominant disorder, there is a 50% chance that the child will inherit the abnormal gene and be affected by the disorder.

Question 24

What type of genetic disorder is Huntington disease?

A) Autosomal recessive
B) X-linked dominant
C) Autosomal dominant
D) Mitochondrial

Answer 24

C) Autosomal dominant

Rationale: Huntington disease is an autosomal dominant genetic disorder that affects the nervous system, characterized by abnormal involuntary movements and progressive dementia.

Question 25

Which pattern of inheritance is indicated if a genetic disorder is transmitted equally to males and females, and can be passed from an affected male to his son?

A) X-linked recessive
B) X-linked dominant
C) Autosomal recessive
D) Autosomal dominant

Answer 25

D) Autosomal dominant

Rationale: Autosomal dominant inheritance is indicated if the genetic disorder is transmitted equally to males and females and can be passed from an affected male to his son, distinguishing it from X-linked inheritance.

Question 26

What is the genetic basis of achondroplasia?

A) It is an X-linked recessive disorder
B) It is an autosomal recessive disorder
C) It is an autosomal dominant disorder
D) It is a mitochondrial disorder

Answer 26

C) It is an autosomal dominant disorder

Rationale: Achondroplasia is an autosomal dominant disorder resulting in disordered growth and abnormal body proportion, caused by a single defective gene overshadowing the normal gene.

Question 27

What is required for an individual to demonstrate signs and symptoms (S/S) of an autosomal recessive disorder?

A) Two mutant or abnormal genes
B) One mutant gene
C) A single dominant gene
D) An X-linked gene

Answer 27

A) Two mutant or abnormal genes

Rationale: Autosomal recessive disorders occur when an individual inherits two mutant or abnormal genes, one from each parent, which are necessary to demonstrate the signs and symptoms of the disorder.

Question 28

What are the characteristics of autosomal recessive inheritance disorders? (SATA)

A) Both parents are carriers of the gene
B) Less common than autosomal dominant disorders
C) Affected individuals have one mutant gene
D) Males and females are equally affected

Answer 28

A) Both parents are carriers of the gene
B) Less common than autosomal dominant disorders
D) Males and females are equally affected

Rationale: Autosomal recessive inheritance disorders are characterized by both parents being carriers of the gene for the child to be affected. These disorders are less common than autosomal dominant disorders, and males and females are equally affected.

Question 29

What is cystic fibrosis?

A) A dysfunction of the nervous system
B) A dysfunction of exocrine glands
C) A blood disorder
D) A genetic disorder affecting muscle growth

Answer 29

B) A dysfunction of exocrine glands

Rationale: Cystic fibrosis is a genetic disorder that involves dysfunction of the exocrine glands, leading to the production of thick mucus that can obstruct airways and affect respiratory and digestive systems.

Question 30

Which genetic disorder involves the abnormal shape of red blood cells and vaso-occlusion?

A) Phenylketonuria (PKU)
B) Cystic fibrosis
C) Spinal muscular atrophy (SMA)
D) Sickle cell anemia

Answer 30

D) Sickle cell anemia

Rationale: Sickle cell anemia is a genetic disorder where red blood cells become abnormally shaped (“sickle”) and can become stuck, causing vaso-occlusion and leading to very painful conditions.

Question 31

Which disorders are included in prenatal and newborn screening for autosomal recessive conditions? (SATA)

A) Cystic fibrosis
B) Spinal muscular atrophy (SMA)
C) Phenylketonuria (PKU)
D) Hemophilia

Answer 31

A) Cystic fibrosis
B) Spinal muscular atrophy (SMA)
C) Phenylketonuria (PKU)

Rationale: Cystic fibrosis, spinal muscular atrophy (SMA), and phenylketonuria (PKU) are included in prenatal and newborn screening for autosomal recessive conditions. Hemophilia is typically X-linked.

Question 32

What is phenylketonuria (PKU)?

A) A genetic disorder affecting the nervous system
B) A disorder of the exocrine glands
C) A deficiency in a liver enzyme needed to process the amino acid phenylalanine
D) A disorder affecting red blood cells

Answer 32

C) A deficiency in a liver enzyme needed to process the amino acid phenylalanine

Rationale: Phenylketonuria (PKU) is a genetic disorder characterized by a deficiency in a liver enzyme required to process the essential amino acid phenylalanine. Without treatment, this can lead to intellectual disability and other health issues.

Question 33

How is sickle cell anemia inherited?

A) Through mutations in the X chromosome
B) When hemoglobin S is on the beta-globin gene
C) By a dominant gene
D) Only through the maternal line

Answer 33

B) When hemoglobin S is on the beta-globin gene

Rationale: Sickle cell anemia is inherited when the hemoglobin S mutation occurs on the beta-globin gene, leading to the production of abnormal hemoglobin and sickle-shaped red blood cells.

Question 34

What is the primary reason for including certain genetic disorders in newborn screening programs?

A) To provide early diagnosis and treatment
B) To ensure uniform genetic profiles
C) To collect data for research purposes
D) To eliminate genetic disorders

Answer 34

A) To provide early diagnosis and treatment

Rationale: The primary reason for including certain genetic disorders in newborn screening programs is to provide early diagnosis and treatment, which can significantly improve health outcomes for affected individuals.

Question 35

Which genetic disorder involves abnormal involuntary movements and progressive dementia?

A) Huntington disease
B) Cystic fibrosis
C) Spinal muscular atrophy (SMA)
D) Polycystic kidney disease

Answer 35

A) Huntington disease

Rationale: Huntington disease is a genetic disorder affecting the nervous system characterized by abnormal involuntary movements and progressive dementia.

Question 36

Why are autosomal recessive disorders less common than autosomal dominant disorders?

A) They require both parents to be carriers
B) They only affect males
C) They are influenced by environmental factors
D) They skip generations

Answer 36

A) They require both parents to be carriers

Rationale: Autosomal recessive disorders are less common than autosomal dominant disorders because they require both parents to be carriers of the mutant gene for the disorder to be expressed in the offspring.

Question 37

What is required for an individual to demonstrate signs and symptoms of an autosomal recessive disorder?

A) One mutant gene
B) Two mutant or abnormal genes
C) A dominant gene
D) An X-linked gene

Answer 37

B) Two mutant or abnormal genes

Rationale: Autosomal recessive inheritance disorders occur when two copies of the mutant or abnormal gene in the homozygous state are necessary to produce the phenotype. Therefore, two abnormal genes are needed for the individual to demonstrate signs and symptoms of the disorder.

Question 38

What are the characteristics of parents of an affected individual with an autosomal recessive disorder? (SATA)

A) Both parents must be carriers of the gene
B) Only one parent needs to be a carrier
C) Parents are heterozygous carriers of the gene
D) Parents show signs and symptoms of the disorder

Answer 38

A) Both parents must be carriers of the gene
C) Parents are heterozygous carriers of the gene

Rationale: For an individual to be affected by an autosomal recessive disorder, both parents must be heterozygous carriers of the gene. These parents are clinically normal but carry the mutant gene, enabling them to pass it on to their offspring.

Question 39

What is the probability that offspring of two carrier parents will be affected by an autosomal recessive disorder?

A) 25%
B) 50%
C) 75%
D) 100%

Answer 39

A) 25%

Rationale: When both parents are carriers of the gene for an autosomal recessive disorder, their offspring have a 25% chance of inheriting two mutant genes, making them affected by the disorder.

Question 40

Which disorders follow an autosomal recessive inheritance pattern? (SATA)

A) Cystic fibrosis
B) Huntington disease
C) Tay-Sachs disease
D) Sickle cell disease

Answer 40

A) Cystic fibrosis
C) Tay-Sachs disease
D) Sickle cell disease

Rationale: Common genetic disorders that follow the autosomal recessive inheritance pattern include cystic fibrosis, Tay-Sachs disease, and sickle cell disease. Huntington disease follows an autosomal dominant inheritance pattern.

Question 41

What is the significance of consanguinity in the context of autosomal recessive inheritance?

A) It eliminates the risk of genetic disorders
B) It increases the chance that both parents will be carriers of the mutant gene
C) It has no effect on genetic inheritance
D) It guarantees that offspring will be affected

Answer 41

B) It increases the chance that both parents will be carriers of the mutant gene

Rationale: Consanguinity (having a common ancestor) increases the chance that both parents will be carriers of the mutant gene, thereby increasing the likelihood of their offspring being affected by an autosomal recessive disorder.

Question 42

Which genetic disorder results from the insufficient activity of the enzyme hexosaminidase A?

A) Cystic fibrosis
B) Phenylketonuria (PKU)
C) Tay-Sachs disease
D) Sickle cell disease

Answer 42

C) Tay-Sachs disease

Rationale: Tay-Sachs disease is a genetic disorder resulting from insufficient activity of the enzyme hexosaminidase A, which is necessary for the breakdown of certain fatty substances in the brain and nerve cells.

Question 43

Which characteristics are true for individuals affected by autosomal recessive disorders? (SATA)

A) They have two copies of the mutant gene
B) They are carriers of the gene
C) They can pass the disorder to their offspring
D) They are always present in multiple generations

Answer 43

A) They have two copies of the mutant gene
C) They can pass the disorder to their offspring

Rationale: Individuals affected by autosomal recessive disorders have two copies of the mutant gene and can pass the disorder to their offspring if the partner is also a carrier.

Question 44

A group of students are reviewing information about genetic inheritance. The students demonstrate understanding of the information when they identify which of the following as an example of an autosomal recessive disorder?

A) Cystic fibrosis

B) Phenylketonuria

C) Tay-Sachs disease

D) Polycystic kidney disease

Answer 44

A) Cystic fibrosis

Question 45

When describing genetic disorders to a group of childbearing couples, the nurse would identify which as an example of an autosomal dominant inheritance disorder?

A) Huntingtons disease

B) Sickle cell disease

C) Phenylketonuria

D) Cystic fibrosis

Answer 45

A) Huntingtons disease

Question 46

What causes chromosomal abnormalities in genetic disorders?

A) Mutations in a single gene
B) Changes in the number or structure of chromosomes
C) Environmental influences alone
D) Traditional patterns of inheritance

Answer 46

B) Changes in the number or structure of chromosomes

Rationale: Chromosomal abnormalities in genetic disorders result from changes in the number of chromosomes or changes in the structure of the chromosomes, rather than mutations in a single gene or traditional patterns of inheritance.

Question 47

Do chromosomal abnormalities follow straightforward patterns of inheritance?

A) No, they do not follow straightforward patterns of inheritance
B) Yes, they follow simple Mendelian patterns
C) They follow dominant inheritance patterns
D) They follow recessive inheritance patterns

Answer 47

A) No, they do not follow straightforward patterns of inheritance

Rationale: Chromosomal abnormalities do not follow straightforward patterns of inheritance, making them different from single gene disorders that follow Mendelian inheritance patterns.

Question 48

On which chromosomes can chromosomal abnormalities occur?

A) Autosomal chromosomes only
B) Sex chromosomes only
C) Both autosomal and sex chromosomes
D) Mitochondrial chromosomes

Answer 48

C) Both autosomal and sex chromosomes

Rationale: Chromosomal abnormalities can occur on both autosomal chromosomes (non-sex chromosomes) and sex chromosomes, affecting the structure or number of these chromosomes.

Question 49

What are the types of changes that can lead to chromosomal abnormalities? (SATA)

A) Increase in the number of chromosomes
B) Decrease in the number of chromosomes
C) Structural changes in chromosomes
D) Only mutations in genes

Answer 49

A) Increase in the number of chromosomes
B) Decrease in the number of chromosomes
C) Structural changes in chromosomes

Rationale: Chromosomal abnormalities can result from an increase or decrease in the number of chromosomes, as well as structural changes in the chromosomes. These abnormalities do not solely result from gene mutations.

Question 50

Why do chromosomal abnormalities differ from traditional genetic inheritance patterns?

A) They are influenced only by environmental factors
B) They involve multiple genes
C) They follow Mendelian inheritance
D) They result from changes in the number or structure of chromosomes

Answer 50

D) They result from changes in the number or structure of chromosomes

Rationale: Chromosomal abnormalities differ from traditional genetic inheritance patterns because they result from changes in the number or structure of chromosomes, rather than following Mendelian patterns of single gene inheritance.

Question 51

What causes chromosomal abnormalities?

A) Mutations in a single gene
B) Changes in the number or structure of chromosomes
C) Environmental influences alone
D) Traditional patterns of inheritance

Answer 51

B) Changes in the number or structure of chromosomes

Rationale: Chromosomal abnormalities arise when the normal complement of 46 chromosomes that produces a karyotype is altered. This can occur due to changes in the number of chromosomes (increase or decrease) or changes in their structure.

Question 52

Which outcomes are often associated with chromosomal abnormalities? (SATA)

A) Major defects
B) Congenital anomalies
C) Intellectual disability
D) Increased resistance to diseases

Answer 52

A) Major defects
B) Congenital anomalies
C) Intellectual disability

Rationale: Chromosomal abnormalities can lead to major defects, congenital anomalies, and intellectual disabilities due to the presence of added or missing genes. They do not generally increase resistance to diseases.

Question 53

What types of chromosomes can be affected by chromosomal abnormalities?

A) Only autosomal chromosomes
B) Only sex chromosomes
C) Both autosomal and sex chromosomes
D) Only mitochondrial chromosomes

Answer 53

C) Both autosomal and sex chromosomes

Rationale: Chromosomal abnormalities can occur on both autosomal chromosomes (non-sex chromosomes) and sex chromosomes, affecting either their number or structure.

Question 54

What is the typical process during which chromosomal abnormalities arise?

A) DNA replication
B) Environmental exposure
C) Protein synthesis
D) Cell division

Answer 54

D) Cell division

Rationale: Chromosomal abnormalities typically arise during cell division, when the normal complement of 46 chromosomes that produces a karyotype is altered, either by an increase or decrease in the number of chromosomes or changes in their structure.

Question 55

What often causes chromosomal abnormalities of number?

A) Mutation in a single gene
B) Nondisjunction during cell division
C) Environmental factors alone
D) Dominant allele inheritance

Answer 55

B) Nondisjunction during cell division

Rationale: Chromosomal abnormalities of number often result from nondisjunction, which is the failure of chromosome pairs to separate properly during cell division, whether during meiosis or mitosis.

Question 56

What are types of polyploidy in humans? (SATA)

A) Triploidy
B) Tetraploidy
C) Monosomy
D) Trisomy

Answer 56

A) Triploidy
B) Tetraploidy
C) Monosomy

Rationale: Polyploidy refers to an increase in the number of haploid sets of chromosomes. In humans, triploidy involves three whole sets of chromosomes (69 chromosomes), and tetraploidy involves four whole sets of chromosomes (92 chromosomes). Monosomy and trisomy are numerical abnormalities but not types of polyploidy.

Question 57

What is the usual outcome of polyploidy in humans?

A) Full-term development
B) Early spontaneous abortion
C) Birth with minor defects
D) No effect on development

Answer 57

B) Early spontaneous abortion

Rationale: Polyploidy usually results in an early spontaneous abortion and is incompatible with life due to the significant alteration in the number of chromosomes.

Question 58

Which chromosomal numerical abnormalities are compatible with development to term?

A) Monosomies involving chromosome 1
B) Polyploidy involving 92 chromosomes
C) Nondisjunction of sex chromosomes
D) Trisomies involving chromosome 13, 18, 21, or X

Answer 58

D) Trisomies involving chromosome 13, 18, 21, or X

Rationale: Numerical abnormalities that can support development to term include trisomies involving chromosomes 13, 18, 21, or X, as these chromosomes carry relatively few genes and can sometimes be compatible with life.

Question 59

What are common trisomies in humans? (SATA)

A) Trisomy 21
B) Trisomy
18 C) Trisomy 13
D) Trisomy 1

Answer 59

A) Trisomy 21
B) Trisomy
18 C) Trisomy 13

Rationale: Common trisomies in humans include trisomy 21 (Down syndrome), trisomy 18, and trisomy 13. Trisomy 1 is not a common or viable trisomy in humans.

Question 60

What is the outcome of monosomies in most cases?

A) Full-term development with no defects
B) Early spontaneous abortion
C) Birth with minor intellectual disabilities
D) Normal development

Answer 60

C) Birth with minor intellectual disabilities

Rationale: Monosomies usually result in early spontaneous abortion because the fetus has only one copy of a particular chromosome instead of the usual pair, which is generally incompatible with life.

Question 61

Which chromosomal abnormality refers to the presence of three of a particular chromosome?

A) Monosomy
B) Trisomy
C) Polyploidy
D) Nondisjunction

Answer 61

B) Trisomy

Rationale: Trisomy refers to the presence of three copies of a particular chromosome instead of the usual two. This can occur in every cell or in a mosaic form, where only some cells have the extra chromosome.

Question 62

How do mosaic forms of numerical chromosomal abnormalities differ from non-mosaic forms?

A) Mosaic forms have only one type of cell
B) Non-mosaic forms are always incompatible with life
C) Mosaic forms have a mix of normal and abnormal cells
D) Non-mosaic forms are always the result of polyploidy

Answer 62

C) Mosaic forms have a mix of normal and abnormal cells

Rationale: Mosaic forms of numerical chromosomal abnormalities involve a mix of normal and abnormal cells, meaning that some cells have the extra or missing chromosome while others do not. This can sometimes result in milder symptoms compared to non-mosaic forms.

Question 63

What causes Trisomy 21?

A) Mutations in a single gene
B) Abnormal cell division involving chromosome 21
C) Environmental factors alone
D) Dominant inheritance pattern

Answer 63

B) Abnormal cell division involving chromosome 21

Rationale: Trisomy 21 results from abnormal cell division involving chromosome 21, leading to three copies of chromosome 21 instead of the usual two.

Question 64

What are characteristics of the mosaic form of Trisomy 21? (SATA)

A) Involves only some cells
B) Every cell is affected
C) Results from mutations in the Y chromosome
D) Can result in milder symptoms compared to the non-mosaic form

Answer 64

A) Involves only some cells
D) Can result in milder symptoms compared to the non-mosaic form

Rationale: The mosaic form of Trisomy 21 involves only some cells, not every cell being affected. This can result in milder symptoms compared to the non-mosaic form, where all cells have the extra chromosome.

Question 65

What is the relationship between maternal age and the risk of having a child with Trisomy 21?

A) Risk decreases with maternal age
B) Risk remains the same regardless of age
C) Risk is highest at age 25
D) Risk increases with maternal age

Answer 65

D) Risk increases with maternal age

Rationale: The risk of having a child with Trisomy 21 increases with maternal age. For example, the risk is 1:1,250 at age 25, 1:1,000 at age 30, 1:400 at age 35, 1:100 at age 40, and 1:40 at age 45.

Question 66

Which congenital defects can be associated with Trisomy 21? (SATA)

A) Mild intellectual disabilities
B) Moderate intellectual disabilities
C) Severe intellectual disabilities
D) No congenital defects

Answer 66

A) Mild intellectual disabilities
B) Moderate intellectual disabilities

Rationale: Congenital defects associated with Trisomy 21 can range from mild to moderate intellectual disabilities. The severity can vary among individuals.

Question 67

Why might defects associated with Trisomy 21 not be seen on an ultrasound?

A) Ultrasound technology cannot detect genetic abnormalities
B) Defects are always visible on ultrasound
C) Some defects may be too subtle to be detected by ultrasound
D) Trisomy 21 only affects internal organs

Answer 67

C) Some defects may be too subtle to be detected by ultrasound

Rationale: Some defects associated with Trisomy 21 may be too subtle to be detected by ultrasound, making it possible for certain abnormalities to go unnoticed during prenatal screening.

Question 68

*What is the term for having three copies of chromosome 21?

A) Monosomy 21
B) Trisomy 21
C) Mosaicism
D) Polyploidy

Answer 68

B) Trisomy 21

Rationale: Trisomy 21 refers to having three copies of chromosome 21, which is the genetic basis for Down syndrome.

Question 69

How does the mosaic form of Trisomy 21 affect the presentation of the disorder?

A) It always leads to more severe symptoms
B) It leads to a higher risk of spontaneous abortion
C) It causes defects in all cells
D) It results in a mix of normal and abnormal cells, potentially leading to milder symptoms

Answer 69

D) It results in a mix of normal and abnormal cells, potentially leading to milder symptoms

Rationale: The mosaic form of Trisomy 21 results in a mix of normal and abnormal cells, which can potentially lead to milder symptoms compared to the non-mosaic form where every cell has the extra chromosome.

Question 70

What is the cause of Down syndrome?

A) Mutation in a single gene
B) Abnormal cell division involving chromosome 21
C) Environmental factors
D) Autosomal recessive inheritance

Answer 70

B) Abnormal cell division involving chromosome 21

Rationale: Down syndrome is caused by abnormal cell division involving chromosome 21, resulting in extra genetic material from this chromosome.

Question 71

Which genetic variations can cause Down syndrome? (SATA)

A) Trisomy 21
B) Mosaic
C) Translocation
D) Duplication

Answer 71

A) Trisomy 21
B) Mosaic
C) Translocation

Rationale: The three genetic variations that can cause Down syndrome include trisomy 21 (three copies of chromosome 21 in all cells), mosaic (some cells with an extra copy of chromosome 21), and translocation (part of chromosome 21 attached to another chromosome).

Question 72

What is the most common genetic variation causing Down syndrome?

A) Mosaic
B) Translocation
C) Trisomy 21
D) Duplication

Answer 72

C) Trisomy 21

Rationale: More than 90% of the cases of Down syndrome are caused by trisomy 21, where the infant has three copies of chromosome 21 instead of the usual two copies.

Question 73

What are characteristic features of children with Down syndrome? (SATA)

A) Small, low-set ears
B) Hyperflexibility
C) Muscle hypotonia
D) Long neck

Answer 73

A) Small, low-set ears
B) Hyperflexibility
C) Muscle hypotonia

Rationale: Characteristic features of children with Down syndrome include small, low-set ears, hyperflexibility, muscle hypotonia, among others.

Question 74

Which of the following features is NOT associated with Down syndrome?

A) Almond-shaped eyes that slant upward
B) Short stature in childhood and adulthood
C) Large, protruding ears
D) Small, white, crescent-shaped spots on the irises

Answer 74

C) Large, protruding ears

Rationale: Children with Down syndrome typically have small, low-set ears that may fold over a little at the pinna, rather than large, protruding ears.

Question 75

What is the significance of the simian crease in children with Down syndrome?

A) It indicates severe cognitive impairment
B) It is a deep crease across the palm
C) It is associated with hearing loss
D) It causes muscle hypotonia

Answer 75

B) It is a deep crease across the palm

Rationale: The simian crease is a deep crease that runs across the palm and is a characteristic feature of children with Down syndrome.

Question 76

How has the outlook for children with Down syndrome changed in recent years?

A) They face more societal integration challenges
B) Their life expectancy has decreased
C) They are becoming increasingly integrated into society
D) Early intervention has little impact

Answer 76

C) They are becoming increasingly integrated into society

Rationale: The outlook for children with Down syndrome has improved, with individuals becoming increasingly integrated into society and participating in diverse activities.

Question 77

What is the average lifespan of individuals with Down syndrome today?

A) 30 years
B) 40 years
C) 50 years
D) 60 years

Answer 77

D) 60 years

Rationale: The average lifespan of individuals with Down syndrome has increased dramatically and is now approaching that of peers without Down syndrome, with an average lifespan of around 60 years.

Question 78

Which features are characteristic of Down syndrome? (SATA)

A) Short neck
B) Flat facial profile with a flat nose
C) Broad, short fingers
D) Long legs

Answer 78

A) Short neck
B) Flat facial profile with a flat nose
C) Broad, short fingers

Rationale: Characteristic features of Down syndrome include a short neck, flat facial profile with a flat nose, and broad, short fingers.

Question 79

Why does the risk of Down syndrome increase with maternal age?

A) Due to increased exposure to environmental toxins
B) Due to higher likelihood of nondisjunction during cell division
C) Due to changes in paternal genes
D) Due to increased physical activity

Answer 79

B) Due to higher likelihood of nondisjunction during cell division

Rationale: The risk of Down syndrome increases with maternal age because the likelihood of nondisjunction (failure of chromosome pairs to separate properly during cell division) increases as women age.

Question 80

Which genetic variation involves part of chromosome 21 becoming attached to another chromosome?

A) Trisomy 21
B) Mosaic
C) Translocation
D) Duplication

Answer 80

C) Translocation

Rationale: Translocation involves part of chromosome 21 becoming attached (translocated) to another chromosome before or at conception, which can cause Down syndrome.

Question 81

What are Trisomy 13 and Trisomy 18?

A) More common than Down syndrome
B) Rarer occurrences than Down syndrome
C) Caused by mutations in a single gene
D) Inherited through autosomal dominance

Answer 81

B) Rarer occurrences than Down syndrome

Rationale: Trisomy 13 and Trisomy 18 are chromosomal abnormalities that are rarer occurrences compared to Down syndrome.

Question 82

What are the common structural abnormalities associated with Trisomy 13 and Trisomy 18?

A) Microcephaly
B) Cleft lip/palate
C) Major heart defects
D) Spina bifida

Answer 82

A) Microcephaly
B) Cleft lip/palate
C) Major heart defects

Rationale: Common structural abnormalities associated with Trisomy 13 and Trisomy 18 include microcephaly, cleft lip/palate, and major heart defects. Spina bifida is not specifically mentioned as related to these trisomies in the text.

Question 83

How are abnormalities in Trisomy 13 and Trisomy 18 usually detected?

A) Blood tests
B) Physical examination at birth
C) Genetic screening postnatally
D) Ultrasound (U/S)

Answer 83

D) Ultrasound (U/S)

Rationale: Abnormalities in Trisomy 13 and Trisomy 18 are usually detected on ultrasound (U/S) due to the severe structural abnormalities associated with these conditions.

Question 84

What is the typical survival outcome for infants with Trisomy 13 and Trisomy 18?

A) Most survive to adulthood
B) Most do not go to term or survive longer than a few days to months
C) They have a normal lifespan
D) They only survive with intensive medical intervention

Answer 84

B) Most do not go to term or survive longer than a few days to months

Rationale: Most infants with Trisomy 13 do not survive longer than a few days, and those with Trisomy 18 may survive beyond a few months. Many do not go to term.

Question 85

Which of the following chromosomal abnormalities is associated with a higher survival rate compared to the others?

A) Trisomy 13
B) Trisomy 18
C) Down syndrome
D) Monosomy

Answer 85

C) Down syndrome

Rationale: Down syndrome (Trisomy 21) is associated with a higher survival rate and better prognosis compared to Trisomy 13 and Trisomy 18.

Question 86

What type of care is typically provided for infants with Trisomy 13 and Trisomy 18?

A) Intensive surgical interventions
B) Supportive care
C) Long-term rehabilitation
D) Palliative care

Answer 86

B) Supportive care
D) Palliative care

Rationale: Infants with Trisomy 13 and Trisomy 18 typically receive supportive care and, in many cases, palliative care, due to the severe structural abnormalities and low survival rates.

Question 87

Which ultrasound findings are associated with Trisomy 18 (Edward syndrome)? (SATA)

A) Intrauterine growth restriction (IUGR)
B) Hydramnios or oligohydramnios
C) Cardiac malformations
D) Single umbilical artery

Answer 87

all of the choices are correct

Rationale: Prenatally, several findings associated with Trisomy 18 (Edward syndrome) can be apparent on ultrasound, including intrauterine growth restriction (IUGR), hydramnios or oligohydramnios, cardiac malformations, and a single umbilical artery.

Question 88

Which serum markers are decreased in maternal serum in cases of Trisomy 18?

A) Maternal serum alpha-fetoprotein (MSAFP) and hCG
B) Thyroxine and insulin
C) Estrogen and progesterone
D) Ferritin and transferrin

Answer 88

B) Thyroxine and insulin

Rationale: Trisomy 18 has been associated with a decrease in maternal serum levels of maternal serum alpha-fetoprotein (MSAFP) and hCG.

Question 89

Which are common abnormalities associated with Trisomy 13 (Patau syndrome)? (SATA)

A) Microcephaly
B) Cardiac defects
C) Polydactyly
D) Spina bifida

Answer 89

A) Microcephaly
B) Cardiac defects
C) Polydactyly

Rationale: Common abnormalities associated with Trisomy 13 (Patau syndrome) include microcephaly, cardiac defects, and polydactyly, among other severe congenital anomalies.

Question 90

What is the life expectancy for most infants with Trisomy 13?

A) A few days
B) A few months
C) One year
D) Several years

Answer 90

A) A few days

Rationale: Life expectancy for most infants with Trisomy 13 (Patau syndrome) is only a few days due to the severity of the congenital anomalies.

Question 91

Which chromosomal condition is characterized by 47 chromosomes with three copies of chromosome 13?

A) Down syndrome
B) Trisomy 18
C) Turner syndrome
D) Trisomy 13

Answer 91

D) Trisomy 13

Rationale: Trisomy 13, or Patau syndrome, is characterized by the presence of 47 chromosomes, with three copies of chromosome 13.

Question 92

What type of care is typically provided for infants with Trisomy 18 and Trisomy 13?

A) Intensive surgical interventions
B) Long-term rehabilitation
C) Supportive care
D) Genetic therapy

Answer 92

C) Supportive care

Rationale: Infants with Trisomy 18 (Edward syndrome) and Trisomy 13 (Patau syndrome) typically receive supportive care due to the severity of the congenital anomalies and the high degree of infant mortality associated with these conditions.

Question 93

What usually causes chromosomal structural abnormalities?

A) Mutations in single genes
B) Incorrect repair of broken chromosome ends
C) Environmental toxins
D) Viral infections

Answer 93

B) Incorrect repair of broken chromosome ends

Rationale: Chromosomal structural abnormalities usually occur when a portion of one or more chromosomes is broken or lost, and during the repair process, the broken ends are rejoined incorrectly, leading to too much or too little genetic material.

Question 94

What are the different forms of altered chromosome structure? (SATA)

A) Deletions
B) Duplications
C) Inversions
D) Mutations

Answer 94

A) Deletions
B) Duplications
C) Inversions

Rationale: Altered chromosome structure can take several forms, including deletions (loss of a portion of the chromosome), duplications (extra chromosomal segment), and inversions (a portion of the chromosome breaks off, inverts, and reattaches).

Question 95

What is a deletion in terms of chromosomal abnormalities?

A) A portion of the chromosome is missing
B) A portion of the chromosome is duplicated
C) A portion of the chromosome is inverted
D) A portion of the chromosome is transferred to another chromosome

Answer 95

A) A portion of the chromosome is missing

Rationale: A deletion occurs when a portion of the chromosome is missing, resulting in a loss of that chromosomal material.

Question 96

What is the most clinically significant structural chromosomal abnormality?

A) Deletion
B) Duplication
C) Inversion
D) Translocation

Answer 96

D) Translocation

Rationale: The most clinically significant structural chromosomal abnormality is a translocation, which occurs when part of one chromosome is transferred to another chromosome, resulting in an abnormal rearrangement.

Question 97

What is the phenotype of individuals who inherit balanced structural abnormalities?

A) Usually phenotypically normal
B) Always show severe clinical consequences
C) Always miscarry
D) Show mosaic patterns

Answer 97

A) Usually phenotypically normal

Rationale: Individuals who inherit balanced structural abnormalities are usually phenotypically normal, but they are at a higher risk for miscarriages and chromosomally abnormal offspring.

Question 98

What clinical findings can result from structural abnormalities of chromosomes?

A) Depend on the size of the rearrangement only
B) Depend on the amount of genetic material involved
C) Are always detectable at birth
D) Have no effect on phenotype

Answer 98

B) Depend on the amount of genetic material involved

Rationale: Clinical findings resulting from structural abnormalities of chromosomes can vary depending on the amount of genetic material involved. Larger rearrangements typically result in more severe clinical consequences.

Question 99

Which part of the chromosome is affected in Cri-du chat syndrome?

A) Long arm of chromosome 5
B) Short arm of chromosome 5
C) Long arm of chromosome 21
D) Short arm of chromosome 21

Answer 99

B) Short arm of chromosome 5

Rationale: Cri-du chat syndrome results from a defect in the short arm of chromosome 5.

Question 100

What characteristic symptom is associated with Cri-du chat syndrome?

A) High-pitched laughing
B) Deep, hoarse voice
C) Cat-like cry
D) No vocalization

Answer 100

C) Cat-like cry

Rationale: Cri-du chat syndrome is characterized by a laryngeal defect that leads to a distinctive “cat-like” cry in affected infants.

Question 101

What are the outcomes for individuals with Cri-du chat syndrome? (SATA)

A) No treatment available
B) Survival through adulthood
C) Require extensive medical intervention
D) Often lead normal lives without support

Answer 101

A) No treatment available
B) Survival through adulthood

Rationale: There is no specific treatment for Cri-du chat syndrome, but individuals with this condition can survive through adulthood with supportive care.

Question 102

What genetic abnormality leads to Cri-du chat syndrome?

A) Deletion of part of chromosome 5
B) Duplication of part of chromosome 21
C) Translocation involving chromosome 18
D) Inversion of part of chromosome 13

Answer 102

A) Deletion of part of chromosome 5

Rationale: Cri-du chat syndrome is caused by a deletion of a portion of the short arm of chromosome 5.

Question 103

How is the characteristic “cat-like” cry produced in Cri-du chat syndrome?

A) Due to a defect in the lungs
B) Due to abnormal vocal cord structure
C) Due to neurological impairment
D) Due to a laryngeal defect

Answer 103

D) Due to a laryngeal defect

Rationale: The characteristic “cat-like” cry in Cri-du chat syndrome results from a laryngeal defect that affects the infant’s ability to produce normal vocal sounds.

Question 104

What are the characteristic symptoms associated with Cri du chat syndrome? (SATA)

A) High-pitched cry in infancy
B) Microcephaly
C) Wide-set eyes
D) Enlarged epiglottis

Answer 104

A) High-pitched cry in infancy
B) Microcephaly
C) Wide-set eyes

Rationale: Characteristic symptoms of Cri du chat syndrome include a high-pitched cry in infancy due to a laryngeal defect, microcephaly, and wide-set eyes. The epiglottis is typically small and floppy, not enlarged.

Question 105

What are the common causes of death in infants with Cri du chat syndrome?

A) Heart defects and respiratory distress
B) Renal failure and liver disease
C) Gastrointestinal obstructions and infections
D) Neurological deficits and seizures

Answer 105

A) Heart defects and respiratory distress

Rationale: Common causes of death in infants with Cri du chat syndrome include pneumonia, aspiration pneumonia, congenital heart defects, and respiratory distress.

Question 106

What additional clinical features may be present in individuals with Cri du chat syndrome? (SATA)

A) Scoliosis
B) Speech delay
C) High birth weight
D) Low-set ears

Answer 106

A) Scoliosis
B) Speech delay
D) Low-set ears

Rationale: Additional clinical features of Cri du chat syndrome may include scoliosis, speech delay, low birth weight and slow growth, hypotonia, and low-set ears, among others.

Question 107

What intervention is recommended for parents of a child diagnosed with Cri du chat syndrome?

A) Genetic counseling
B) Immediate surgical intervention
C) Hormone replacement therapy
D) Vaccination against common infections

Answer 107

A) Genetic counseling

Rationale: Parents of a child diagnosed with Cri du chat syndrome should be referred for genetic counseling to understand the genetic implications, recurrence risks, and supportive care options.

Question 108

At what age is Fragile X syndrome usually diagnosed?

A) At birth
B) By age 1
C) By age 3
D) By age 5

Answer 108

C) By age 3

Rationale: Fragile X syndrome is typically diagnosed by age 3. This allows for early intervention and support for the developmental challenges associated with the condition.

Question 109

What characterizes Fragile X syndrome at the chromosomal level?

A) Extra copies of chromosome 21
B) Deletion of part of chromosome 5
C) Translocation involving chromosome 13
D) Breaks and gaps in the X chromosome

Answer 109

D) Breaks and gaps in the X chromosome

Rationale: Fragile X syndrome is characterized by breaks and gaps in the X chromosome, which lead to the symptoms and features associated with the disorder.

Question 110

What are common physical features associated with Fragile X syndrome? (SATA)

A) Intellectual disability
B) Large ears
C) Long face
D) Short stature

Answer 110

B) Large ears
C) Long face

Rationale: Common physical features associated with Fragile X syndrome include large ears and a long face. Intellectual disability is a characteristic symptom, not a physical feature, and short stature is not typically associated with Fragile X.

Question 111

What type of symptoms are often seen in individuals with Fragile X syndrome?

A) Cardiovascular symptoms
B) Respiratory symptoms
C) Autism-type symptoms
D) Gastrointestinal symptoms

Answer 111

C) Autism-type symptoms

Rationale: Individuals with Fragile X syndrome often exhibit autism-type symptoms, such as social and communication challenges, repetitive behaviors, and sensory sensitivities.

Question 112

Is Fragile X syndrome more common in males or females?

A) Males
B) Females
C) Equally common in males and females
D) More common in neither

Answer 112

B) Females

Rationale: Fragile X syndrome is more common in females. Although males typically have more severe symptoms, the condition is more frequently diagnosed in females.

Question 113

How does Fragile X syndrome affect life expectancy?

A) Significantly shortens life-span
B) Shortens life-span by a few years
C) Life-span is unaffected
D) Extends life-span

Answer 113

C) Life-span is unaffected

Rationale: Life expectancy for individuals with Fragile X syndrome is generally unaffected, meaning they can have a normal life expectancy.

Question 114

What intervention is crucial for parents with a child diagnosed with Fragile X syndrome?

A) Immediate surgical intervention
B) Genetic counseling
C) Hormone replacement therapy
D) Long-term use of antibiotics

Answer 114

B) Genetic counseling

Rationale: Genetic counseling is crucial for parents with a child diagnosed with Fragile X syndrome to understand the genetic implications, recurrence risks, and supportive care options.

Question 115

What are common features of Fragile X syndrome? (SATA)

A) Large head
B) Long face
C) Short attention span
D) Deep-set eyes

Answer 115

A) Large head
B) Long face
C) Short attention span

Rationale: Common features of Fragile X syndrome include a large head, long face, and short attention span. Deep-set eyes are not typically associated with Fragile X syndrome.

Question 116

How does Fragile X syndrome affect males compared to females?

A) Females are carriers and males exhibit full symptoms
B) Males are carriers and females show full symptoms
C) Both males and females are carriers
D) Both males and females exhibit full symptoms

Answer 116

A) Females are carriers and males exhibit full symptoms

Rationale: Typically, females become carriers and are mildly affected, while males who receive the X chromosome with the fragile site exhibit the full effects of Fragile X syndrome.

Question 117

What behaviors are associated with Fragile X syndrome? (SATA)

A) Hand flapping
B) Speech delay
C) Inflexible behavior
D) Improved attention span

Answer 117

A) Hand flapping
B) Speech delay
C) Inflexible behavior

Rationale: Behaviors associated with Fragile X syndrome include hand flapping, speech delay, and inflexible behavior. An improved attention span is not a characteristic symptom.

Question 118

What types of therapies are usually needed for individuals with Fragile X syndrome?

A) Genetic therapy and long-term antibiotics
B) Chemotherapy and radiation
C) Hormone replacement therapy
D) Speech, occupational, and physical therapy

Answer 118

D) Speech, occupational, and physical therapy

Rationale: Individuals with Fragile X syndrome usually require speech, occupational, and physical therapy, as well as special education and counseling, to address developmental challenges.

Question 119

What distinguishes sex chromosome abnormalities from autosomal chromosomal abnormalities?

A) They are usually more severe in their clinical effects
B) They are typically less severe in their clinical effects
C) They do not affect sexual development
D) They are inherited through mitochondrial DNA

Answer 119

B) They are typically less severe in their clinical effects

Rationale: Sex chromosome abnormalities are usually less severe in their clinical effects compared to autosomal chromosomal abnormalities.

Question 120

What are common effects of sex chromosome abnormalities? (SATA)

A) Infertility
B) Growth abnormalities
C) Enhanced cognitive abilities
D) Behavioral and learning problems

Answer 120

A) Infertility
B) Growth abnormalities
D) Behavioral and learning problems

Rationale: Common effects of sex chromosome abnormalities include infertility, growth abnormalities, and behavioral and learning problems. Enhanced cognitive abilities are not associated with these conditions.

Question 121

Which sex chromosome abnormalities are gender-specific?

A) Down syndrome and Turner syndrome
B) Fragile X syndrome and Klinefelter syndrome
C) Klinefelter syndrome and Turner syndrome
D) Turner syndrome and Patau syndrome

Answer 121

C) Klinefelter syndrome and Turner syndrome

Rationale: Klinefelter syndrome (in males) and Turner syndrome (in females) are examples of gender-specific sex chromosome abnormalities.

Question 122

What impact do sex chromosome abnormalities have on individuals’ lives?

A) Most affected individuals lead normal lives
B) All affected individuals have severe disabilities
C) They typically result in a short lifespan
D) They are always fatal in early childhood

Answer 122

A) Most affected individuals lead normal lives

Rationale: Many individuals affected by sex chromosome abnormalities lead essentially normal lives, although they may experience issues related to sexual development, infertility, and learning problems.

Question 123

What is the cause of Prader-Willi Syndrome?

A) Defect on the maternal chromosome 15
B) Defect on the paternal chromosome 15
C) Defect on chromosome 21
D) Defect on the X chromosome

Answer 123

B) Defect on the paternal chromosome 15

Rationale: Prader-Willi Syndrome results from a defect on the paternal chromosome 15, which can involve a deletion, two copies from the mother, or an imprinting defect.

Question 124

How does Prader-Willi Syndrome affect males and females?

A) Males are more affected than females
B) Females are more affected than males
C) Males and females are affected equally
D) Only males are affected

Answer 124

C) Males and females are affected equally

Rationale: Prader-Willi Syndrome affects males and females equally.

Question 125

Which clinical features are associated with Prader-Willi Syndrome? (SATA)

A) Obesity in childhood
B) Excessive eating
C) Behavioral challenges
D) Hypertonia

Answer 125

A) Obesity in childhood
B) Excessive eating
C) Behavioral challenges

Rationale: Clinical features of Prader-Willi Syndrome include obesity in childhood, excessive eating, and behavioral challenges. Hypotonia, not hypertonia, is also a feature of the syndrome.

Question 126

What is hypotonia in the context of Prader-Willi Syndrome?

A) Increased muscle tone
B) Decreased muscle tone
C) Normal muscle tone
D) Spastic muscle tone

Answer 126

B) Decreased muscle tone

Rationale: Hypotonia refers to decreased muscle tone, which is a characteristic feature of Prader-Willi Syndrome.

Question 127

Which genetic defects can lead to Prader-Willi Syndrome? (SATA)

A) Deletion on maternal chromosome 15
B) Two copies of chromosome 15 from the mother
C) Imprinting defect on paternal chromosome 15
D) Duplication of chromosome 21

Answer 127

B) Two copies of chromosome 15 from the mother
C) Imprinting defect on paternal chromosome 15

Rationale: Genetic defects that can lead to Prader-Willi Syndrome include having two copies of chromosome 15 from the mother (uniparental disomy) and imprinting defects on the paternal chromosome 15.

Question 128

How does Prader-Willi Syndrome typically present in childhood?

A) Hypoactivity and low appetite
B) Obesity and excessive eating
C) Tall stature and hyperactivity
D) Normal growth and development

Answer 128

B) Obesity and excessive eating

Rationale: Prader-Willi Syndrome typically presents in childhood with obesity and excessive eating due to an insatiable appetite and lack of satiety.

Question 129

What are common behavioral challenges associated with Prader-Willi Syndrome?(SATA)

A) Compulsive behaviors
B) Anxiety and tantrums
C) Social withdrawal
D) Enhanced cognitive abilities

Answer 129

A) Compulsive behaviors
B) Anxiety and tantrums

Rationale: Common behavioral challenges associated with Prader-Willi Syndrome include compulsive behaviors, anxiety, and tantrums. Social withdrawal and enhanced cognitive abilities are not typically associated with the syndrome.

Question 130

What impact does Prader-Willi Syndrome have on muscle tone?

A) It decreases muscle tone
B) It increases muscle tone
C) It causes normal muscle tone
D) It causes variable muscle tone

Answer 130

A) It decreases muscle tone

Rationale: Prader-Willi Syndrome leads to decreased muscle tone (hypotonia), which is a significant feature of the disorder.

Question 131

Which population is equally affected by Prader-Willi Syndrome?

A) Males only
B) Females only
C) Males and females
D) Children only

Answer 131

C) Males and females

Rationale: Prader-Willi Syndrome affects both males and females equally, with no gender predilection.

Question 132

What is the chromosomal cause of Turner Syndrome?

A) Extra X chromosome
B) Single X chromosome
C) Deletion of part of chromosome 15
D) Translocation of chromosome 21

Answer 132

B) Single X chromosome

Rationale: Rationale: Turner Syndrome is caused by the presence of a single X chromosome instead of the usual two sex chromosomes (XX).

Question 133

Which population is affected by Turner Syndrome?

A) Males only
B) Females only
C) Both males and females
D) Children only

Answer 133

B) Females only

Rationale: Turner Syndrome affects females only and has an incidence of approximately 1 in 2,000 female births.

Question 134

What are the reproductive effects of Turner Syndrome? (SATA)

A) Affects fertility
B) Failure to develop breasts
C) Normal development of ovaries
D) Failure to develop ovaries

Answer 134

A) Affects fertility
B) Failure to develop breasts
D) Failure to develop ovaries

Rationale: Turner Syndrome affects fertility and the development of sex organs, leading to failure to develop breasts and ovaries.

Question 135

How does the severity of Turner Syndrome defects vary?

A) All cases are severe
B) All cases are mild
C) Defects can range from mild to severe
D) Only mild cases are diagnosed

Answer 135

C) Defects can range from mild to severe

Rationale: The severity of defects in Turner Syndrome can range from mild to severe, affecting various aspects of development.

Question 136

When are diagnoses of Turner Syndrome commonly made?

A) Only in adulthood
B) Only in infancy
C) In adolescence, childhood, and neonatal period
D) During prenatal screening only

Answer 136

C) In adolescence, childhood, and neonatal period

Rationale: Diagnoses of Turner Syndrome are commonly made in adolescence, childhood, and the neonatal period. One-third of diagnoses occur in each of these stages.

Question 137

How is Turner Syndrome increasingly being diagnosed?

A) Through physical examination
B) Through prenatal screening/testing
C) Through genetic counseling
D) Through MRI scans

Answer 137

B) Through prenatal screening/testing

Rationale: Turner Syndrome is increasingly being diagnosed through prenatal screening and testing, which helps identify the condition before birth.

Question 138

What are common diagnostic features for Turner Syndrome?

A) Presence of a single X chromosome
B) Multiple copies of X chromosomes
C) Normal development of sexual characteristics
D) Presence of male reproductive organs

Answer 138

A) Presence of a single X chromosome

Rationale: The presence of a single X chromosome is a common diagnostic feature for Turner Syndrome, which affects females and impacts their sexual development and fertility.

Question 139

What is the chromosomal cause of Turner Syndrome?

A) Single X chromosome
B) Extra X chromosome
C) Deletion of part of chromosome 15
D) Translocation of chromosome 21

Answer 139

A) Single X chromosome

Rationale: Turner Syndrome is caused by a missing portion or all of the X chromosome, resulting in a single X chromosome.

Question 140

What are common clinical manifestations of Turner Syndrome? (SATA)

A) Low posterior hairline
B) Webbing of the neck
C) Tall stature
D) Broad skeletal abnormalities

Answer 140

A) Low posterior hairline
B) Webbing of the neck
D) Broad skeletal abnormalities

Rationale: Common clinical manifestations of Turner Syndrome include a low posterior hairline, webbing of the neck, and broad skeletal abnormalities. Tall stature is not a characteristic feature.

Question 141

At what stages are most cases of Turner Syndrome diagnosed?

A) Only in adulthood
B) Only in infancy
C) In adolescence, childhood, and neonatal period
D) During prenatal screening only

Answer 141

C) In adolescence, childhood, and neonatal period

Rationale: Diagnoses of Turner Syndrome are commonly made in adolescence, childhood, and the neonatal period, with one-third diagnosed in each of these stages.

Question 142

What type of therapy is typically given to individuals with Turner Syndrome to induce puberty and stimulate growth?

A) Chemotherapy
B) Hormone replacement therapy
C) Antibiotic therapy
D) Gene therapy

Answer 142

B) Hormone replacement therapy

Rationale: Hormone replacement therapy is typically given to individuals with Turner Syndrome to induce puberty and stimulate continued growth.

Question 143

Which secondary sex characteristics are underdeveloped in Turner Syndrome? (SATA)

A) Breast development
B) Ovaries
C) Secondary hair growth
D) Testes

Answer 143

A) Breast development
B) Ovaries
C) Secondary hair growth

Rationale: Secondary sex characteristics such as breast development, ovaries, and secondary hair growth are often underdeveloped in Turner Syndrome. Testes are not applicable as the condition affects females only

Question 144

What is the general intelligence level of most females with Turner Syndrome?

A) Severely impaired
B) Below average
C) Normal intelligence
D) Above average

Answer 144

C) Normal intelligence

Rationale: Most females with Turner Syndrome are of normal intelligence and usually live essentially typical lives, despite their physical and reproductive challenges.

Question 145

What is the chromosomal pattern of Klinefelter Syndrome?

A) XX
B) XY
C) XXY
D) XYY

Answer 145

C) XXY

Rationale: Klinefelter Syndrome is characterized by the presence of an extra X chromosome, resulting in the XXY chromosomal pattern.

Question 146

Which population is affected by Klinefelter Syndrome?

A) Females only
B) Both males and females
C) Males only
D) Children only

Answer 146

C) Males only

Rationale: Klinefelter Syndrome affects only males due to the presence of the extra X chromosome.

Question 147

What impact does the extra X chromosome have on males with Klinefelter Syndrome?

A) Increased testosterone production
B) Abnormal development of the testicles
C) Normal development of the testicles
D) Increased production of sperm

Answer 147

B) Abnormal development of the testicles

Rationale: The extra genetic material causes abnormal development of the testicles, resulting in decreased production of sperm and male sex hormones.

Question 148

What are common clinical manifestations of Klinefelter Syndrome? (SATA)

A) Mild intellectual disability
B) Small testes
C) Tall stature
D) Abundant facial hair

Answer 148

A) Mild intellectual disability
B) Small testes
C) Tall stature

Rationale: Common clinical manifestations of Klinefelter Syndrome include mild intellectual disability, small testes, and tall stature. Sparse, rather than abundant, facial hair is also a characteristic feature.

Question 149

What is gynecomastia in the context of Klinefelter Syndrome?

A) Enlarged breast tissue in males
B) Excessive body hair
C) Increased muscle mass
D) Enhanced testosterone levels

Answer 149

A) Enlarged breast tissue in males

Rationale: Gynecomastia refers to the development of enlarged breast tissue in males, which is a common feature of Klinefelter Syndrome.

Question 150

Which type of therapy can improve symptoms resulting from testosterone deficiency in Klinefelter Syndrome?

A) Chemotherapy
B) Antibiotic therapy
C) Testosterone replacement therapy
D) Gene therapy

Answer 150

C) Testosterone replacement therapy

Rationale: Testosterone replacement therapy can improve symptoms resulting from the deficiency in testosterone in individuals with Klinefelter Syndrome.

Question 151

What developmental challenges are associated with Klinefelter Syndrome? (SATA)

A) Learning disabilities
B) Delayed speech and language development
C) Increased libido
D) Short stature

Answer 151

A) Learning disabilities
B) Delayed speech and language development

Rationale: Developmental challenges associated with Klinefelter Syndrome include learning disabilities and delayed speech and language development. Decreased, rather than increased, libido and tall stature are also characteristic features.

Question 152

What surgical intervention may be done to reduce gynecomastia in Klinefelter Syndrome?

A) Hysterectomy
B) Orchiectomy
C) Rhinoplasty
D) Mastectomy

Answer 152

D) Mastectomy

Rationale: Surgery to reduce gynecomastia in males with Klinefelter Syndrome may involve mastectomy, which is the removal of breast tissue.

Question 153

How is the life expectancy of individuals with Klinefelter Syndrome?

A) Significantly reduced
B) Shortened by a few years
C) Normal
D) Extended

Answer 153

C) Normal

Rationale: The life expectancy of individuals with Klinefelter Syndrome is generally normal, meaning they can live a typical lifespan despite the associated symptoms.