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Foundations EXAM 2 > Genetics > Flashcards

Genetics Flashcards

1
Q

Define Genes

A

Hereditary units of DNA transmitted from one generation to another; code for proteins

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2
Q

Define Locus

A

The specific location of a gene on a chromosome

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3
Q

Define Alleles

A

Different versions of a gene; humans have 2 alleles for each autosomal gene

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4
Q

Define Chromosomes

A
  • Structure composed of genes located in nucleus of a cell
  • Chromosomes can be distinguished from each other by overall length and position of centromere (divides chromosome into 2 arms of varying length)
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5
Q

Define Homologous chromosomes

A

Have the same genes at the same loci, one maternal and one paternal

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6
Q

Define Genome

A

The genetic information contained in the cells, on the chromosomes, for a particular species

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7
Q

Define a Mutation

A

-A change in some part of the DNA code

  • Can be spontaneous or induced by exposure to mutagenic chemicals or radiation
  • Varying effects depending on where in the gene code the mutation occurred
  • Net result of a mutation may be a change in physical appearance or other some other trait
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8
Q

Define Autosome

A
  • Any chromosome that is not a sex chromosome (humans have 22 pairs of autosomes)
  • Humans have one allosome pair (sex chromosome pair)
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9
Q

What are the number of Chromosomes a person has

A

-Somatic cells contain one set of chromosomes from female parent and one homologous set from male parent

  • Homologous chromosomes are similar in size, structure, and gene composition
  • Humans have 22 pairs of autosomes, and 1 pair of sex chromosomes (allosomes) for 23 total pairs in each cell
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10
Q

compare Haploid VS Diploid numbers of chromosomes

A
  • Haploid number (n): the number of chromosomes in sex cells/gametes (n=23)
  • Diploid number (2n): the total number of chromosomes in somatic cells (2n=46)
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11
Q

Describe human chromosomes (physically)

A
  • Short arm is the p arm
  • Long arm is the q arm
  • Each chromosome (except sex chromosomes) is numbered consecutively according to length beginning with longest chromosome first
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12
Q

compare Autosomes VS Allosomes

A
  • Autosomes: All chromosomes except sex chromosomes

- Allosomes: Sex chromosomes

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13
Q

Describe sex chromosomes in males and females

A
  • Human males have Heteromorphic chromosomes (X and Y)
  • Genetic factors on the Y determine maleness
  • Human females have two morphologically similar X’s
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14
Q

Describe Mitosis

A
  • The process by which all somatic cells become descendants of one original cell
  • One exact copy of each chromosome is made and distributed through the division of original cell into two daughter cells
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15
Q

Describe Meiosis

A
  • The process by which gamete cells are produced (egg and sperm)
  • Resulting gametes have 23 new chromosomes (one member of each of the pairs), with new combos of the original maternal and paternal copies
  • Occurs only in specialized germ cells of gonads
  • 2 consecutive cell divisions producing cells with half the original chromosome number. diploid 2n –> haploid n
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16
Q

Describe differences in Gametogenesis in Males VS Females

DRAW THIS OUT

A

-MALE: Diploid primordial cells in testes become spermatogonia –> 4 sperm cells (spermatozoa), each is haploid (n)

-FEMALE: Diploid primordial cells in ovaries become
oogonia –> Diploid primordial cells in ovaries become
oogonia

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17
Q

Describe Genotype

A

-All of the alleles of an organism

  • Homozygous – contains the same alleles at a single locus
  • Heterozygous – contains 2 different alleles at a single locus
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18
Q

Describe Phenotype

A
  • A measurable trait an organism has

- Result of gene products that interact in a given environment

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19
Q

Describe Dominant allele

A

Phenotype can be seen in both the heterozygote and homozygote

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20
Q

Describe a Carrier

A

Heterozygous individual with a recessive allele that’s hidden from phenotypic view by the dominant, normal allele

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21
Q

Describe Recessive allele

A

Produces this phenotype only when its paired allele is identical

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22
Q

What does the Punnett square illustrate?

A

A monofactorial cross – a mating in which a single gene is analyzed

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23
Q

Albinism Punnett square example… DRAW IT OUT!

A=dominant, pigment-producing allele
a=recessive, albino (no pigment) allele
What is the result?

A

Produces 3 genotypes, 2 phenotypes

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24
Q

Describe Codominance

A
  • When two alleles for a trait are equally expressed (example: AB blood type)
  • When alleles lack complete dominant and recessive relationships and are both observed phenotypically (expressed at the same time)
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25
Q

Describe Incomplete dominance

A
  • Heterozygotes have phenotypes that have both alleles visible as a blend (one allele isn’t expressed over the other)
  • Makes a third phenotype that’s a blending of the two
  • Human examples: wavy hair – it’s a blend that’s seen when a person with straight hair has a child with a person with curly hair; skin color
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26
Q

Describe Penetrance

A

The probability that individuals in a population who have a particular gene combination will show the condition

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27
Q

Describe a Genetic marker

A

Sequence of DNA with a known location on a chromosome

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28
Q

Describe Expression

A
  • The components of the phenotype that are exhibited in an individual
  • Example: myotonic muscular dystrophy
  • Phenotype may include myotonia, cataracts, narcolepsy, balding, infertility
  • 2 people carrying this gene may express it differently: one may have cataracts and one has narcolepsy and grip myotonia
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29
Q

Describe Anticipation

A
  • Genetic diseases that increase in severity or have earlier onset with each successive generation
  • Examples: Fragile X, Huntington, myotonic muscular dystrophy
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30
Q

Describe Chromosomal Abnormalities

A
  • Can be numerical or structural

- Most common type is aneuploidy – abnormal number

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31
Q

What is balanced chromosomal abnormalities and two examples of it?

A

-No net loss or gain of chromosomal material

1) Balanced translocation – rupture of a chromosome resulting in the pieces “re-sticking” in the wrong combinations
2) Inversion – a chromosome piece is lifted out, turned around, and reinserted

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32
Q

Describe Unbalanced chromosomal abnormalities

A

-Additional or missing information (Deletion or Insertion)

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33
Q

Describe Unbalanced translocation

A
  • Tends to arise as an offspring of a balanced carrier

- Example: Robertsonian translocation

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34
Q

Describe Robertsonian translocation

A
  • Involve any 2 out of chromosomes 13, 14, 15, 21, and 22
  • They are all acrocentric (centromeres are close to the end)
  • Results in formation of a “new” chromosome
  • The bigger chromosome can produce an unbalanced gamete
  • Those involving chromosome 21 can produce gametes with 2 copies; upon fertilization, can produce Trisomy 21
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35
Q

What are the Standard Symbols in Pedigree Language?

A
  • Male -square
  • Female – circle
  • Diagonal line through symbol – deceased
  • Shaded symbol – affected with trait
  • Half-shaded symbol – carrier of trait
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36
Q

What are the Standard Lines in Pedigree Language?

A
  • Relationship – line between individuals
  • Sibship – horizontal line showing siblings
  • Line of descent – line showing offspring
  • Individual line – attaches to sibship line
  • Two hash marks – divorced or separated (or no longer in a relationship)
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37
Q

Contrast Consultand VS Proband

A
  • Consultand: The person seeking genetic advice. Represented by an arrow on pedigree. Can be healthy or a person with a condition
  • Proband: The affected individual
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38
Q

What are some Pedigree Tips?

A
  • Draw siblings in birth order from left to right; include either their age or their year of birth (1, 2, 3)
  • Each generation goes on the same horizontal plane (I, II, III)
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39
Q

Describe Patterns of Inheritance and the Pedigree: Autosomal dominant

A
  • 65% of human monogenic disorders
  • Mutation in a single allele can cause disease
  • Examples: Huntington’s Disease
  • Affected individuals are HH or Hh (homozygous dominant or heterozygous)
  • Those with genotypes hh are normal
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40
Q

Describe Characteristics of Autosomal dominant diseases

A
  • Vertical pattern: Transmission passes from parent to offspring
  • Multiple generations affected
  • Variable expressivity: Affected individuals in same family may show varying degrees of phenotypic expression (severity)
  • Reduced penetrance: Some with the genetic mutation may not show phenotype, making it appear that it “skipped” a generation
  • Males and females affected equally
  • Male to male transmission can be seen
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41
Q

Describe Patterns of Inheritance and the Pedigree: Autosomal Recessive

A
  • 25% of human monogenic disorders
  • 2 copies of diseased allele required for expressing the phenotype
  • Tends to involve enzymes or receptors
  • Rare
  • Males and females equally affected
  • Horizontal inheritance: Multiple affected offspring
  • Often occurs in the context of consanguinity (In-family breeding)
  • Heterozygous carriers of a defective allele are usually clinically normal
  • Example: Cystic fibrosis
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42
Q

Describe Characteristics of Autosomal Recessive diseases

A
  • Horizontal pattern
  • Single generation affected
  • Males and females affected equally
  • Inheritance is from both parents, each being a heterozygote/carrier
  • Each offspring has a 25% chance of being affected, and a 50% chance of being a carrier
  • Higher association with consanguity
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43
Q

Describe Patterns of Inheritance and the Pedigree: X-Linked

A
  • 5% of human monogenic disorders
  • Risk of developing disease due to a mutant x chromosome differs between the sexes
  • Males are hemizygous (heterozygous) for mutant allele on the X: More likely to develop a mutant phenotype regardless if the mutation is dominant or recessive
  • The terms “x-linked dominant” and “x-linked recessive” therefore only apply to females
  • Heterozygous females usually normal or mild
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44
Q

Describe Characteristics of X-Linked diseases

A
  • No male to male transmission is possible
  • Unaffected males do not transmit the phenotype
  • All daughters of an affected male are heterozygous carriers
  • Males usually more severely affected than females

Examples:

1) X-linked dominant: Alport’s Syndrome, Fragile X Syndrome
2) X-linked recessive: Wiskott-Aldrich Syndrome, Duchenne muscular dystrophy

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45
Q

Describe Patterns of Inheritance and the Pedigree: Multifactorial/Complex Disease

A

-Caused by interactions of variations in multiple genes and environmental factors

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46
Q

Describe Genetic susceptibility genes

A

-These genes make a person susceptible to a disorder, and certain environmental factors trigger the susceptibility.
-These are increasingly being identified for complex conditions such as:
Cancer
Diabetes
Asthma
Heart disease
Mental illness
Cleft lip/cleft palate

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47
Q

Describe Sporadic cancer vs. inherited cancer

A
  • Sporadic cancer is more likely

- Most cancer is NOT inherited, but the predisposition to cancer IS inherited

48
Q

Describe Down Syndrome

A

-Gamete has two copies of chromosome 21: Trisomy 21
-Trisomy 21 is cause of 95% of cases of Down Syndrome
4% due to Roberstonian translocation
-Most common, non-lethal trisomy, chromosomal abnormality in live births
-Prevalence: 1:500 pregnancies
-Increase incidence with advancing maternal age
Age 35- 1:400
Age 45- 1:35

49
Q

Describe Prenatal testing for Down Syndrome

A
  • Quad screen: maternal serum AFP, estriol, hCG, inhibin-alpha
  • Nuchal translucency: Ultrasound of fetus’ neck

-Combination of these tests determines the thickness of the skin of the fetus, which helps determine if he/she has Down Syndrome

50
Q

Describe Down Syndrome characteristics

A
  • Intellectual disability
  • Characteristic facial appearance
  • 40% have cardiac defects
  • 75% hearing loss
  • > 50% visual problems
  • 7% have GI defects
  • Increased social skills in childhood
  • Half of adults with Down syndrome develop Alzheimer disease
51
Q

Describe Trisomy 18

A
  • AKA Edwards Syndrome
  • Second most common autosomal trisomy after trisomy 21 that goes to full term
  • Usually from 3 copies of 18, but translocation can occur
  • Many die before birth or in first month
52
Q

Describe Characteristics of Trisomy 18

A
  • Kidney and heart defects
  • Developmental delay
  • Club foot (Rocker bottom feet)
  • Low set ears, small jaw
53
Q

Describe Trisomy 18 birth statistics

A
  • 1:5000 live born infants
  • Increased risk with advanced maternal age
  • IUGR: Intrautero Growth Restriction
  • Highly lethal in-utero – 85% lost between 10 weeks’ gestation and term
  • 50% die in first week of life
  • 2% 1 year survival rate
54
Q

Describe Trisomy 13 birth statistics

A
  • AKA Patau syndrome
  • Increased risk with advanced maternal age
  • 1:16000 live births
  • Severe intellectual disability
  • Many children die within first days or weeks of life
55
Q

Describe Trisomy 13 characteristics

A
  • Cleft lip or palate
  • Seizures
  • Small jaw
  • Polydactyly
  • Heart defects, brain/spinal cord abnormalities
56
Q

Describe Trisomy 13 Etiology

A
  • Most cases of Trisomy 13 ????????????
  • Some caused by Robertsonian translocation involving chromosomes 13 and 14: A part of chromosome 13 gets attached to chromosome 14 during formation of gametes. Affected people have 2 normal copies of 13 plus an extra copy attached to another chromosome
57
Q

Describe Cri-du-Chat Syndrome

A
  • Deletion of part of short arm of chromosome 5
  • Partial monosomy: when only a portion of a chromosome has one copy instead of two
  • Most cases are from a spontaneous mutation
  • Cat-like cry of affected children due to abnormal larynx development
  • Intellectual disability, wide set eyes, low ears
  • 1:50,000 births
  • Can be detected in utero with CVS (Chorionic Villus Sampling)
58
Q

Describe Klinefelter’s Syndrome *

A
  • Extra X chromosome, 47 XXY
  • Occurs during gametogenesis
  • Affects male physical and cognitive development
  • Accounts for many first trimester losses
  • Physical traits become more apparent after puberty
  • Most common sex chromosome aneuploidy in males
  • Hypogonadism, infertility
  • Gynecomastia, reduced hair
59
Q

Describe Turner Syndrome *

A
  • 45 X, affects development in females
  • Monosomy
  • Gonadal dysgenesis* –> Non-functional ovaries
  • Short stature
  • Broad chest
  • Webbed neck
  • Amenorrhea
  • Infertility
  • Cardiovascular abnormalities
60
Q

Describe Huntington’s Disease signs and symptoms *

A
  • A neurodegenerative disease – progressive brain disorder
  • Causes uncontrolled movements, emotional problems, and loss of thinking ability, changes in personality
  • Early signs: depression, irritability, poor coordination, trouble learning
  • Involuntary jerking movements: chorea
  • Adult onset: genetic defect is latent for 3-5 decades, then manifests as progressive neuronal dysfunction
61
Q

Describe Huntington’s Disease genetics *

A
  • Genetic defect: HD gene on chromosome 4 that codes for a unique protein called huntingtin
  • CAG trinucleotide repeat
  • Normal: 10-35 repeats
  • In HD: 36-120 repeats
  • Abnormal protein (Glutamate) causes microscopic deposits of protein in neurons
  • Most cases are inherited, but some occur as new spontaneous mutations
  • Autosomal dominant: Only human disorder of complete dominance –> Anticipation
  • Average time from symptom onset to death is 15 years
62
Q

Describe Alzheimer’s Disease

A
  • A neurodegenerative disease
  • Progressive mental deterioration: memory loss, confusion, disorientation
  • Most common form of dementia in older individuals
  • Dementia
  • 65% from Alzheimer’s Disease
  • 35% vascular in nature
63
Q

Describe Population of Alzheimer’s Disease

A
  • Usually begins after age 60; risk increases with age
  • Death usually occurs within 10 years
  • People with parent, sibling, or child with AD are at increased risk
64
Q

Describe Pathophysiology of Alzheimer’s Disease

A
  • Loss of cholinergic neurons in brain (loss of acetylcholine)
  • Formation of plaques and tangles
  • Atrophy of brain
  • Resultant effect – blocked communication
65
Q

What are the two forms of Alzheimer’s Disease?

A

1) Familial… AKA early onset AD

2) Sporadic… AKA late onset AD

66
Q

Describe Describe Familial AD

A
  • Many members of multiple generations affected
  • Symptoms start before age 65
  • Mutations on chromosomes 1, 14, or 21: Induce formation of a “sticky” protein that forms clumps in the brain
  • Rare - <5% of cases of AD
  • Autosomal dominant: 50% chance of developing early onset AD if one parent has it
67
Q

Describe Describe Sporadic AD

A
  • Usually develops after age 65
  • Accounts for most cases of AD
  • One gene has been shown to increase risk
  • Chromosome 19 apolipoprotein E (APOE) gene
  • Not everyone carrying the gene develops disease

-Definitive diagnosis: autopsy-plaques and tangles of nervous tissue*

68
Q

Describe Risk factors for Hereditary Breast and Ovarian Cancer Syndrome

A

Gender
Age
Family history

69
Q

Describe the Mode of inheritance for Hereditary Breast and Ovarian Cancer Syndrome

A

Up to 10% of breast and ovarian cancers are caused by known predisposing genetic factors

70
Q

Describe Clinical manifestations of Hereditary Breast and Ovarian Cancer Syndrome

A
  • Early age of breast cancer onset (< 50)
  • FH of both breast and ovarian cancer
  • Increased bilateral cancers
  • Increased development of both cancers in same person
  • Increased incidence of prostate cancer in family
  • Male breast cancer
71
Q

What are the TWO major cancer susceptibility genes

A
  • BRCA1 and BRCA2: Are tumor suppressor genes
  • Normally control cell growth and death, and DNA repair and stability
  • If a person has one mutated copy of either gene, their cancer risk goes up
72
Q

Describe BRCA1

A
  • First gene associated with breast cancer
  • BRCA1 on chromosome 17
  • Mutation is inherited in autosomal dominant manner
  • Not all families with this gene get hereditary breast cancer
73
Q

Describe BRCA2

A
  • Second gene associated with breast cancer
  • BRCA2 on chromosome 13
  • Mutations is inherited in autosomal dominant manner
  • Associated with male breast cancer, ovarian cancer, prostate cancer, and pancreatic cancer
74
Q

Describe Genetic testing for Hereditary Breast and Ovarian Cancer Syndrome

A
  • Preferable to first test an individual who is affected by cancer before testing unaffected family members
  • Helps to identify whether a detectable BRCA1 or BRCA2 mutation could be responsible for the cancer
  • An individual can inherit a BRCA1 or BRCA2 mutation yet never develop cancer
75
Q

Describe Colorectal Cancer

A
  • Results from the interaction of both genetic and environmental factors
  • Genetic predisposition is the main risk factor in only a small proportion of people
  • Diet, exercise, smoking, obesity are stronger risk factors in most people
  • May occur sporadically or from familial inheritance
  • Most are from sporadic mutations and occur randomly
  • Many cancer syndromes include colon cancer
76
Q

Describe Types of hereditary colon cancer

A

1) Familial colorectal cancer
2) Hereditary colorectal cancer syndromes
- Arise from specific mutations in genes that code for susceptibility to cancer
- Familial adenomatous polyposis (FAP) <1%
- Hereditary nonpolyposis colorectal cancer (HNPCC, Lynch Syndrome) 2-3%

77
Q

Describe Colorectal Cancer family history

A

-Patterns within a family that exist without identifying a specific mutation are labeled as familial colorectal cancers
-A family history of one or more people with colorectal cancer or premalignant polyps is considered a positive FH
-May be due to:
Chance alone
Shared exposure to a carcinogen or diet/lifestyle factors
Combination of gene mutations and environmental risk factors

78
Q

Describe Familial adenomatous polyposis (FAP)

A
  • <1% of all colorectal cancers
  • Pattern of inheritance: autosomal dominant
  • Children of patient with FAP should have genetic screening by age 10 years
  • Once diagnosis of FAP is established, total colectomy is recommended before age 20 years
79
Q

Describe Genetic mutation that affects Familial adenomatous polyposis (FAP)

A
  • Mutation in APC (adenomatous polyposis coli) gene
  • Hundreds to thousands of polyps in colon beginning in adolescence
  • APC is a tumor suppressor gene on chromosome 5
  • Cancers develop in 20’s
  • Risk of developing colorectal cancer is near 100%, usually before age 50
  • Time from polyp to cancer development is 10+ years
80
Q

Describe Hereditary Nonpolyposis Colorectal Cancer (HNPCC)

A
  • AKA Lynch Syndrome
  • 2-3% of all colorectal cancers
  • Pattern of inheritance: autosomal dominant
  • Genetic mutation: a mutation in one of many genes that code for DNA repair
  • More rapid transition from adenoma to cancer than FAP – cancers occur earlier, 30’s and 40’s
81
Q

What does Nonpolyposis refers to?

A

-The fact that colorectal cancer can occur when a small number or no polyps are present

82
Q

Describe Hereditary Nonpolyposis Colorectal Cancer (HNPCC) cancer rates

A
  • Approx. 50% chance of cancer in women, approx. 70% in men
  • Associated with the formation of other cancers
  • Uterus, ovaries, stomach, urinary tract, small bowel, bile ducts
83
Q

Describe Hereditary Nonpolyposis Colorectal Cancer (HNPCC) maintenance

A

-Regular colonoscopy starting age 25 for relatives
Or beginning 5 years younger than the age of diagnosis of the youngest affected family member
-Upper endoscopy every 2 years to screen for gastric cancer
-Screening for endometrial and ovarian cancer in women at age 25-35

84
Q

Describe Chronic Myelogenous Leukemia *

A
  • A myeloproliferative disorder
  • More common in men
  • Median age at presentation is 55 years
85
Q

Describe Genetic defects of Chronic Myelogenous Leukemia *

A

1) Translocation between chromosomes 9 and 22
2) *Philadelphia chromosome (22) –> Produces a protein that codes for an enzyme that causes too many stem cells to develop into WBCs

86
Q

Describe the Pathophysiology of Chronic Myelogenous Leukemia

A
  • Increased production of abnormal white blood cells that are nonfunctional
  • These large numbers of abnormal WBCs take up bone marrow space meant for healthy WBCs, RBCs, and platelets
87
Q

Describe the Clinical presentation of Chronic Myelogenous Leukemia

A
  • Insidious onset, slow progression over months to years of infections, anemia, bleeding
  • Fever, night sweats fatigue
  • Diagnosis involves bone marrow aspiration for karyotype
88
Q

Describe Hemophilia *

A
  • Bleeding disorders caused by mutations in genes that code for coagulation proteins
  • Mutation on F8 or F9 genes, located on the X chromosome
89
Q

Compare Hemophilia A VS Hemophilia B *

A
  • Mutation in F8 gene causes factor VIII deficiency
  • Results in hemophilia A (classic hemophilia)
  • More common
  • Mutation in F9 gene causes factor IX deficiency
  • Results in hemophilia B (Christmas Disease)
90
Q

Describe Pattern of inheritance of Hemophilia *

A
  • X-linked recessive pattern
  • Genes associated are on the X chromosome
  • Most people affected are males
91
Q

Describe the Clinical manifestations of Hemophilia *

A
  • *hemarthroses** (spontaneous bleeding into a joint)
  • Bleeding into muscles, and other soft tissues
  • Prolonged bleeding or oozing of blood after injury or surgery
  • Severity of symptoms can be variable
92
Q

Describe Sickle Cell Disease Pathophysiology *

A
  • Atypical hemoglobin molecules (hemoglobin S)
  • Distorts the red blood cell into a crescent shape
  • Abnormally shaped RBCs break down prematurely
  • Mutation on HBB gene
93
Q

Describe Clinical manifestations of Sickle Cell Disease

A
  • Anemia, infections, episodic pain

- Shortness of breath, fatigue, delayed growth

94
Q

Describe inheritance of Sickle Cell Disease *

A
  • Autosomal recessive
  • Most common in people whose ancestors came from Greece, Africa, Turkey, Italy, Arabian Peninsula, India, South America, Central America, Caribbean
95
Q

Describe Cystic Fibrosis Pattern of inheritance *

A
  • Autosomal recessive

- Two copies of mutated gene are needed for disease to be expressed

96
Q

Describe Genetic mutation of Cystic Fibrosis *

A
  • Mutation in the CFTR gene (cystic fibrosis transmembrane conductance regulator)
  • CFTR codes for a protein that regulates chloride channels in epithelial cells
  • When mutated, a defective protein is made, causing a disruption of chloride and water transport - water balance in secretions is disrupted
97
Q

Describe the Clinical manifestations of Cystic Fibrosis *

A
  • Causes thick, sticky mucous obstructing airways in lungs and ducts in pancreas
  • Can affect pancreas, intestines, GU tract, hepatobiliary system, and exocrine glands
98
Q

Describe Symptoms of Cystic Fibrosis *

A
  • Difficulty breathing, infections in lungs
  • Problems with nutrient digestion
  • Buildup of mucous prevents pancreatic enzymes from reaching intestine
  • Failure to thrive, poor growth rate
  • Meconium ileus – newborn intestinal obstruction due to thick fecal waste products
99
Q

What is the most common morbidity associated with Cystic Fibrosis? *

A
  • Pulmonary disease
  • Pulmonary system can’t defend against pathogens well – leads to sinusitis and bronchitis
  • Nasal polyps, nosebleeds, chronic sinus infections common in CF patients
  • Thick mucous builds up in lower airways causing obstruction
100
Q

Describe Other associated info of Cystic Fibrosis *

A
  • Common genetic disease in the white population in the US
  • Disease incidence: 1 in 3500 white newborns
  • Carrier incidence: 1 in 25
  • Most cases diagnosed by age 1
  • Sweat chloride test – primary test for diagnosis
101
Q

Describe the Sweat chloride test *

A
  • Defective chloride channel doesn’t allow chloride to be reabsorbed
  • Concentration of chloride in sweat is elevated in CF
  • Genetic testing used to confirm results
102
Q

Describe Marfan Syndrome *

A
  • Autosomal dominant
  • Results from either an inherited mutation or a new mutation of the fibrillin-1 gene (FBN1)
  • Causes defects in connective tissue affecting multiple systems
  • Bones
  • Ligaments
  • Muscles
  • Blood vessels
  • Heart valves
103
Q

Describe Clinical manifestations of Marfan Syndrome *

A
  • Tall stature
  • Long, thin arms and legs
  • Arm span wider than body height
  • Long, narrow face
  • High arched palate
  • Overcrowded teeth
  • Scoliosis
  • Hyperflexible joints
  • Chest deformities
104
Q

Describe Key primary features of Marfan Syndrome *

A

Dislocated lens of the eye – vision problems

Aortic aneurysm/dissection

105
Q

Describe Heart defects in Marfan Syndrome *

A

-Heart defects are major cause of morbidity and mortality

  • Mitral valve prolapse, aortic valve regurgitation
  • Both of these can cause SOB, fatigue, palpitations
106
Q

Advice for people with Marfan Syndrome

A

Affected individuals are advised to avoid contact sports, caffeine, and decongestants due to increased stress placed on CV system

107
Q

Describe Neurofibromatosis Type I *

A
  • AKA von Recklinghausen disease
  • Autosomal dominant
  • Mutation on NF1 gene on chromosome 17
108
Q

What is the NF1 gene on chromosome 17? What would you see in a mutation here? *

A

-Tumor suppressor gene

  • Mutation results in:
  • 1) Growth of neurofibromas - benign tumors that grow on nerves of skin and brain (Subcutaneous tumors)
  • 2) Changes in skin pigmentation
  • Café-au-lait spots
  • Flat patches on skin darker than surrounding area
  • Lisch nodules in iris
  • Freckles in axillae and groin
109
Q

Describe Diagnostic features for Neurofibromatosis Type I *

A
  • 1.5 cm or larger café-au-lait spot post puberty or 6 or more café-au-lait spots 0.5 cm or larger in before puberty
  • 2 or more neurofibromas
  • Axillary or inguinal freckling (Crowe sign)
  • Optic glioma
  • 2 or more Lisch nodules
  • 1st degree relative with NF1
110
Q

Describe Polycystic Kidney Disease Pathophysiology

A
  • Clusters of fluid filled sacs develop in kidneys
  • Affects ability to filter the blood properly
  • Kidneys become enlarged and can fail
111
Q

Describe Polycystic Kidney Disease Clinical manifestations

A
  • Hypertension
  • Back pain
  • Hematuria
  • UTIs, kidney stones
112
Q

Describe Other associations of Polycystic Kidney Disease

A
  • Liver cysts
  • Heart valve abnormalities
  • Increased risk of aortic aneurysm and brain aneurysm
113
Q

What are the two forms of Polycystic Kidney Disease

A

1) Autosomal dominant – sx start in adulthood
- 1 in 1000; PKD1 and PKD2 genes
- Usually inherited (90% of the time)

2) Autosomal recessive – rare, lethal early in life
- 1 in 30,000
- PKHD1 gene

114
Q

Describe Congenital Abnormalities

A
  • Approximately 10% of all newborns have some birth defect. Ranges from minor biochemical problem to severe physical deformity
  • Caused by variety of biological, chemical, and physical agents
  • Contributors: mutant genes, chromosomal defects, multifactorial components
  • Biggest cause of birth defects: unknown etiology
115
Q

What is Teratology?

A

-Study of abnormal development

116
Q

What are Teratogens?

A
  • Anything capable of disrupting embryonic or fetal development and producing malformations
  • Critical period for teratogenic effects is 3-16 weeks’ gestation
  • Timing of exposure determines which systems are affected
117
Q

Newborn Screening

A
  • Biochemical analysis that determines whether certain proteins (enzymes) are present or absent
  • These are typically autosomal recessive conditions
  • Referred to as “inborn errors of metabolism”
  • Inherited defect in one or more enzymes
  • Newborn screening checks for many of these metabolic disorders
  • 1st test: baby is 24-36 hours old
  • 2nd test: 1st office visit, between 5-10 days

Foundations EXAM 2 (3 decks)

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