DISEASES OF CHROMOSOMAL ABNORMALITIES GROUP 6 | BSMLS 2C | CYTOGENETICS

Question 1

The most common genetic etiology of moderate intellectual disability(IQ between 25-74).

Answer 1

Down syndrome

Question 2

Down syndrome is a genetic condition where a person is born with an extra copy of________. This means that they have a total of 47 chromosomes instead of 46.

Answer 2

chromosome 21

Question 3

Down syndrome

Karyotype notation:

Answer 3

47 XY +22 (male) or 47 XX +21 (female)

Question 4

Accounts for 95% of Down Syndrome cases. A person who is affected have 3 separate copies of chromosome 21 insted of 2 copies in its cells.

Answer 4

TRISOMY 21

Question 5

A rare variation that occurs when one chromosome breaks off. The chromosome 21 is in 3 copies (like trisomy 21),but part of the chromosome breaks off and joins itself to another chromosome. It is Caused by extra genes in the egg or sperm of parents.

Answer 5

TRANSLOCATIONAL DOWN SYNDROME

Question 6

2% of DS cases Some of their cells have 3 copies of Chromosome 21, while other cells have the typical 2 copies of said chromosome. They may have fewer features of the condition.

Answer 6

MOSAIC DOWN SYNDROME

Question 7

ndividuals who are affected by this disease are more prone to congenital heart defects (50%) such as atrioventricular septal defects, ventricular septal defects, isolated secundum atrial septal defects, patent ductus arteriosus, and tetralogy of Fallot.

Answer 7

Down syndrome

Question 8

Down syndrome diagnosis

Answer 8

Amniocentesis

Typically performed between 15-20 weeks of pregnancy.

Chronic Villus Sampling (CVS)

Almost the same with amniocentesis, but done earlier at 10-12 weeks. Insertion of catheter through the cervix, to the placenta to get tissue.

Question 9

Also known asTrisonomy 18

Answer 9

EDWARD SYNDROME

Question 10

EDWARD SYNDROME

It has 47 total number of chromosomes (extra copy).

+
denotes that the aneuploidy (trisomy) happens in the _____

Karyotype notation:

Answer 10

chromosome 18

47 XY +18 (male) or 47 XX +1 (female)

Question 11

It is very uncommon for fetuses with this condition to survive. Most babies with this syndrome will die in the utero, and if delivered, shortly after being born, it will die. Because of the extra copy of chromosome 18 resulting to several organ defects and malformation.

Answer 11

Edward syndrome

Question 12

Most babies with Edwards’ syndrome have an extra chromosome 18 present in all cells

Answer 12

FULL EDWARD’S SYNDROME

Question 13

A small number of babies with Edwards’ syndrome (about 1 in 20) have an extra chromosome 18 in just some cells. This can lead to milder effects of the condition, depending on the number and type of cells that have the extra chromosome. Most babies with this type of Edward’s syndrome who are born alive will live for at least a year, and they may live to adulthood.

Answer 13

MOSAIC EDWARD’S SYNDROME

Question 14

A very small number of babies with Edwards’ syndrome (about 1 in 100) have only a section of the extra chromosome 18 in their cells, rather than a whole extra chromosome 18

Answer 14

PARTIAL EDWARD’S SYNDROME

Question 15

CLINICAL MANIFESTATIONS

Newborns affected with this syndrome has an average life span of 2-4 months.

Answer 15

Edward syndrome

Question 16

is a condition that is caused by an extra chromosome number 16 (three copies instead of two).

Answer 16

Trisomy 16

Question 17

The most commonly observed autosomal aneuploidy in spontaneous abortion.

Karyotype notation:

Answer 17

47 XX +16 (female) or 47 XY +16 (male)

Question 18

47 XX +16 (female) or 47 XY +16 (male)

Answer 18

TRISOMY 16

Question 19

A fetus with full trisomy 16 has an extra copy of chromosome 16 in every cell of the body. This abnormality usually results in a first-trimester miscarriage.

Answer 19

FULL TRISOMY 16

Question 20

A rare variation that occurs when a fetus has an extra copy of the chromosome 16 in some cells of the body, but not every cell.

Babies with mosaic trisomy 16

often survive, and though they’re typically born early and with a low birth weight, many grow to a normal weight and height by toddlerhood.

Answer 20

MOSAIC TRISOMY 16

Question 21

Variations of trisomy 16 — called 16p or 16q — can also occur when

every cell in a fetus’s body has changes to part, but not all, of a

chromosome. In some cases

babies with trisomy 16p or 16q

can survive, but they can have developmental delays, intellectual differences, behavioral problems

and distorted facial features

Answer 21

PARTIAL TRISOMY 16

Question 22

Live born infants with mosaic______ may have intrauterine growth restriction (IUGR), orofacial clefting, cardiac defects, renal abnormalities, and other medical conditions.

Mosaicism for trisomy\____ can occur with variable phenotype. There is increased prevalence of adverse pregnancy outcomes such as preeclampsia, IUGR, spontaneous preterm birth, and stillbirth in pregnancies with trisomy ___

Answer 22

trisomy 16

Question 23

DIAGNOSIS

Specialized genetic tests such as:

karyotyping, fluorescence in situ hybridization (FISH), quantitative polymerase chain reaction (qPCR), and microarray

These confirmatory tests are generally performed on cells from chorionic villus sampling (CVS) or amniocentesis during pregnancy, on cord blood or peripheral blood sample after the baby is born, or on products of conception (POC) in the case of a miscarriage.

Answer 23

Trisomy 16

Question 24

Also known as Patau Syndrome

Answer 24

TRISOMY 13

Question 25

clinical syndrome that occurs when all or some cells of the body contain an extra copy of chromosome 13. Karytoype notation (chromosomal shorthand):

Answer 25

TRISOMY 13 47, XX, +13 or 47, XY, +13

Question 26

However, 20% of Patau syndrome can result from an______ translocation and rarely by mosaicism. Recently, there have been reports of several cases of longer survival due to aggressive medical therapy

Answer 26

unbalanced

Question 27

CLINICAL MANIFESTATIONS Cleft lip often midline; Flexed fingers with polydactyly; Ocular hypotelorism (decreased distance between the eyes or pupils), Bulbous nose; Low-set, malformed ears; Microcephaly (smaller than normal head size); Cerebral malformation, especially holoprosencephaly (brain does not divide into 2); Microphthalmia (abnormally small eye or eyes); Cardiac malformations; Scalp defects; Hypoplastic or absent ribs; Visceral and genital anomalies

Answer 27

Trisomy 13

Question 28

Diagnosis of trisomy 13

Answer 28

Prenatal: 1) Chorionic villi sampling 2) Amniocentesis 3) Fetal free DNA analysis Prenatal ultrasound after 17 weeks gestation is most sensitive in detecting the abnormalities of Patau syndrome

Question 29

Trisomy 13 Treatment and management

Answer 29

Intensive treatment of Patau syndrome is controversial due to the universally poor prognosis of patients despite treatment. Infants diagnosed with Patau syndrome may need postdelivery oxygenation and ventilation; this may require intubation due to facial defects. Surgeries for common defects including herniorrhaphy, cleft lip repair, feeding tube placement, or corrective orthopedic surgeries

Question 30

is the most common sex chromosomal aneuploidy in males This syndrome is the most common cause of hypogonadism and infertility in males and the most common sex chromosome aneuploidy in humans. Those with this abnormality have normal intelligence but are at risk for learning disabilities.

Answer 30

Klinefelter syndrome

Question 31

Klinefelter sundrome The precise genetic etiology of supernumerary X chromosomes ______was identified in 1959

Answer 31

(47,XXY)

Question 32

Extra X chromosomes lead to testicular hyalinization, fibrosis, and hypofunction

Answer 32

Klinefelter

Question 33

SIGNS & SYMPTOMS The syndrome describes males with: Tall stature, Small testicles after puberty Gynecomastia Azoospermia Reduced facial hair Reduced body hair Reduced muscle strength Osteoporosis Feminine fat distribution Varicose veins Low energy

Answer 33

Klinefelter

Question 34

A diagnosis of_______ syndrome is confirmed with blood tests. The only way to confirm the presence of an extra chromosome is by a karyotype test

Answer 34

klinefelter’s

Question 35

Prevention & Treatment/Management No Cure should be monitored closely for speech, learning, and behavioral problems should be referred for early evaluation and treatment as needed Testosterone, LH, and FSH levels should be checked at 11-12 yr of age Replacement therapy with a testosterone preparation is recommended once FSH and LH begin to rise above normal Lifelong Testosterone treatment/ therapy

Answer 35

Klinefelter

Question 36

Jacobs syndrome, also known as_____ syndrome, is a rare genetic condition that occurs in about 1 out of 1000 male children. It belongs to a group of conditions known as "sex chromosome trisomies", with______ syndrome being the more common type. This condition was initially discovered in the 1960s

Answer 36

47,XYY Klinefelter's

Question 37

Signs and symptoms Macroorchidism Tall stature Macrocephaly Hypertelorism

Answer 37

Jacob’s syndrome

Question 38

DIAGNOSIS After birth, diagnosis is made using karyotype analysis from a sample of the patient's blood. 47,XYY men who are being seen for infertility should receive a semen analysis, testicular ultrasound, and bloodwork to measure reproductive hormones

Answer 38

Jacob’s syndrome

Question 39

PREVENTION AND TREATMENT Should receive genetic counseling Should receive genetic counseling Speech therapy Occupational therapy (may be needed hypotonia is present)

Answer 39

Jacob’s syndrome

Question 40

______[ syndrome is the most common sex chromosome abnormality in women.

Answer 40

Turner or XO

Question 41

______ syndrome is a random genetic disorder that affects women.

Answer 41

Turner's

Question 42

The karyotype revealed absence of an X chromosome

Answer 42

(45,X) TURNER’S SYNDROME

Question 43

SOME HAVE AN ISOCHROMOSOME WITH THE LONG ARM OF THE X CHROMOSOME DUPLICATED, BUT THE SHORT ARM ABSENT

Answer 43

Turner’s syndrome

Question 44

SIGNS & SYMPTOMS Shorter than their peers, final adult height of 4'7 low-set ears drooping of the eyelids do not ovulate or menstruate and breasts do not develop They cannot hear certain frequencies of sound.

Answer 44

Turner’s syndrome

Question 45

DIAGNOSIS Before birth, NONINVASIVE PRENATAL TESTING (NIPT) determining the risk that the fetus will be born with. After birth, MICROARRAY TEST compared px’s sample with normal control to find missing or extra chromosome pieces.

Answer 45

Turner’s syndrome

Question 46

TREATMENT NO CURE GROWTH HORMONE ESTROGEN REPLACEMENT THERAPY CARDIAC SURGERY

Answer 46

Turner’s syndrome

Question 47

The name of the syndrome, meaning cat cry, was coined after the main clinical finding of a high-pitched, monochromatic cat-like cry that happens because of a missing piece (deletion) of a chromosome

Answer 47

CRI DU CHAT SYNDROME

Question 48

CRI DU CHAT SYNDROME Researchers believe that the loss of a specific gene,________, is associated with severe intellectual disability in some people with this condition.

Answer 48

CTNND2

Question 49

The _________ provides instructions for making a protein called delta-catenin

Answer 49

CTNND2 (catenin delta 2) gene

Question 50

Cri-du-chat (cat's cry) syndrome, also known as ____ syndrome, is a chromosomal condition that is caused by a deletion of the short arm of chromosome 5.

Answer 50

5p- (5p minus)

Question 51

SIGNS & SYMPTOMS a high-pitched, cat-like cry or weak cry low birth weight a small head eyes spaced wide apart abnormalities of the palate, such as an unusually narrow and high palate Intellectual disability and delayed development

Answer 51

Cri du chat

Question 52

difficulties with suckling and swallowing high rate of infections, such as ear and upper respiratory tract infections eye problems, such as a squint (strabismus heart defect

Answer 52

Cri du chat

Question 53

DIAGNOSIS CHROMOSOMAL TESTING The diagnosis of______ syndrome is generally made in the hospital at birth. The cat-like cry is the most prominent clinical feature in newborn children and is usually diagnostic for the cri du chat syndrome

Answer 53

cri du chat

Question 54

TREATMENT NO CURE physiotherapy to improve poor muscle tone speech therapy communication alternatives, such as sign language, since speech is usually delayed, often severely

Answer 54

5p-

Question 55

usually associated with a delition of the long arm of paternal chromosome 15.

Answer 55

Prader willi syndrome

Question 56

It is a complex genetic disorder that affects many parts of the body. It is characterized by a combination of physical features, behavioral problems, and intellectual disability

Answer 56

Prader willi syndrome

Question 57

PRADER WILLI SYNDROME The error occurs randomly during sperm or egg formation, and is not inherited from either parent. There are three main ways in which the genetic error can occur:

Answer 57

Deletion Maternal disomy Imprinting defect

Question 58

: A small piece of the father's chromosome 15 is missing. This is the most common cause of PWS.

Answer 58

Deletion

Question 59

: Both copies of chromosome 15 come from the mother, and there is no copy from the father.

Answer 59

Maternal disomy

Question 60

: A defect occurs in the genetic imprinting process, which determines which parent's genes are active in certain regions of the chromosome.

Answer 60

Imprinting defect

Question 61

SIGNS & SYMPTOMS hyperphagia- excessive hunger that is why they are obese for paternal deletion. hypothalamic dysfunction- which can lead to problems with temperature regulation, sleep, and sexual development hypotonia- weak muscle tone in infancy Cognitive impairment, mental retardation, Speech impediments problems- such as stubbornness, temper tantrums, and obsessive-compulsive behaviors Short stature Narrow forehead Small hands and feet Light skin and hair

Answer 61

Prader willi

Question 62

Prader willi Karyotype

Answer 62

karyotype 47,XY,+min(15)(pter->q11.1:) maternal UPD 15--case

Question 63

Treatment for ______syndrome focuses on managing the symptoms and improving the quality of life for the affected individual. Growth hormone therapy: Diet and nutrition management: Behavioral therapy: Occupational therapy: Speech therapy: Sex hormone therapy

Answer 63

Prader-Willi