Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pathology Exam 1 > Genetic Diseases > Flashcards

Genetic Diseases Flashcards

1
Q

define gene

A

a segment of DNA that codes for synthesis of a polypeptide; determines a component of a trait

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

define allele

A

term describing a pair of like genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

define autosomes

A

the 22 pairs of chromosomes (all except the sex chromosomes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

define dominant

A

among alleles, typically one 1 determines the attribute. that gene is dominant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

define recessive

A

the allele of the pair that doesn’t have influence on the attribute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

define codominant

A

when both alleles have equal influence on an attribute and the attribute represent a blend

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

define hemizygous

A

possessing only the gene (without the allele) as occurs with the X chromosome because the Y chromosome has no corresponding allele

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

define penetrance

A

the outward expression of the gene makeup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

define expressivity

A

the degree to which a dominant gene expresses itself in a phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

define forme fruste

A

a minimum expression of a dominant gene in the phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

define proband

A

the original person that presents a genetic disease to your attention (ex. your patient)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

define kindred

A

the probands whole family

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

define inherited

A

derived from your parent’s genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

define familial

A

runs in families - often but not necessarily inherited

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

define germline mutation

A

occurs in all body cells and germ cells and is thus passed on to children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

define somatic mutation

A

occurs in an isolated group of cells and is not heritable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

define hereditary disorders

A

transmitted through gametes from parents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

define syndrome

A

group of symptoms which consistently occur together, or a condition characterized by a set of associated symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

trinucleotide repeats are made up of what and have which nucleotides

A

3 base pair sequences and is GC rich

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

define cytogenetics

A

the study of inheritance in relation to the structure and function of chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is the short arm of the chromosome

A

p arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the long arm of the chromosome

A

q arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how is this read: 7 q 3 1.2

A

chromosome 7
q arm
region 3
band 1
sub-band 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the breakdown of chromosome location in order

A

chromosome number, arm, region, band and sub-band

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

define reciprocal translocation

A

fragments are exchanged between 2 chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

define balanced translocation

A

all genetic material is maintained

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

define Roberstsonian translocation

A

between acrocentric chromosomes (centromere close to end = short p arm) resulting in subsequent loss of p arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

define isochromosome

A

centromere divides horizontally rather than vertically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

define ring chromosome

A

the ends fuse together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

define monosomy

A

loss of a whole chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

define trisomy

A

gain of a whole chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what does this mean: 46, XX, t(2;5)(q31;p14)

A

46 = chromosome total count
XX = female
t = translocation between chromosomes 2 and 5
q31 on chromosome 2 switched with p14 on chromosome 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

are epigenetic modification heritable

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

define epigenetics

A

changes in the regulation of gene expression that are not dependent on gene sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what are epigenetic changes often caused by

A

chemical modifications of the DNA or chromosomal proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what are four examples of epigenetic changes

A
  • DNA methylation (mCpG islands = lots of C’s and G’s) typically cause silencing
  • histone modifications: acetylation, methylation, phosphorylation, or other mods can silence or enhance gene expression
  • non-coding RNAs; miRNAs and lncRNAs have regulatory functions to alter gene expression
  • genomic imprinting; DNA or histone methylation silences one chromosome’s allele while the non-imprinted allele on the other chromosome is expressed
    —> imprinted chromosomes are at greater risk to express mutational events
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

feature of autosomal dominant defects

A

50% reduction in normal gene function causes clinical manifestations if the gene regulates a metabolic pathway or codes for structural proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

feature of autosomal recessive defects

A

enzyme defects can be compensated for 50% of normal gene function such that enzyme defects often show autosomal recessive inheritance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

define pleiotropy

A

single gene mutation having many phenotypic effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

define genetic heterogeneity

A

a mutation at several different loci causes that same trait

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

define modifier genes

A

affect the severity or extent of the phenotypes caused by a mutation

42
Q

Marfan Sx is what kind of disease

A

autosomal dominant

43
Q

Marfan is a mutation of what

A

fibrillin (ECM component of elastic fibers)

44
Q

Marfan is an example of what

A

pleiotropy –> elastic fibers are present in many tissues throughout the body so the disease has wide ranging effects

45
Q

Marfan clinical defects: (5)

A
  • elongated hiatus: slender, long legs, arms and fingers
  • hyperextensible joints
  • oral: high arched palate
  • ocular: dislocation of lens
  • cardiavasc.: elastic fiber fragmentation of the tunica media –> aortic dilation and dissection
46
Q

Ehlers-Danlos has defect in what

A

structure or function of collagen

47
Q

t/f ehler-danlos is dominant

A

F. can be dominant or recessive

48
Q

Ehlers-Danlos clinical features: (3)

A
  • very stretchable and fragile skin
  • hypermobile joints
  • internal complications: colon rupture, ocular fragility, and diaphragmatic hernia
49
Q

two forms of muscular dystrophy

A

Duchenne MD = severe
Becker MD = milder

50
Q

MD is what kind of disease

A

X-linked recessive = expected to only affect males

51
Q

MD has a mutation in what

A

dystrophin - whose protein protects m cells during contraction, links internal cytoskeleton to the ECM

52
Q

MD clinical presentation

A
  • progressive damage, inability to repair leads to m cell death and replacement by scar tissue and fat
  • m weakness in childhood leading to death in early adulthood
53
Q

familial hypercholesterolemia (FH) is what kind of disease

A

autosomal dominant

54
Q

FH has a mutation in what

A

loss of function mutation of the LDL receptor

55
Q

FH mutation leads to what:

A
  • elevated LDL in the plasma
  • lack of LDL uptake into liver cells induces HMG-CoA to activate cholesterol synthesis
56
Q

clinical features of FH

A
  • high blood LDL and cholesterol cause premature atherosclerosis and coronary artery disease
  • cholesterol deposits in skin (xanthomas)
57
Q

cystic fibrosis is what kind of disease

A

autosomal recessive

58
Q

cystic fibrosis has a mutation in what, which causes what

A

CFTR gene cases protein misfolding and degradation in the ER

59
Q

cystic fibrosis mutation also causes a defect in what, which leads to what

A

Cl- ion transport, which causes very thick, mucous secretions from exocrine glands

60
Q

clinical features of cystic fibrosis

A
  • chromic pulmonary infections (pseudomonas aeruginosa)
  • pancreatic exocrine insufficiency due to progressive fibrosis leads to protein, fat malabsorption, and potentially fat-soluble vitamin deficiency, diarrhea
  • fatty liver –> cirrhosis
  • salty sweat gland secretion
61
Q

neurofibromatosis is what kind of disease

A

autosomal dominant

62
Q

neurofibromatosis is a ______________ disease of the skin

A

Von Recklinghausen

63
Q

T/F neurofibromatosis has highly variable expressivity

A

T

64
Q

neurofibromatosis has a mutation in what

A

NF1 (neurofibromin) gene leads to increase cell growth

65
Q

neurofibromatosis clinical presentation

A
  • neurofibromas: benign skin tumors
  • cafe-au-lait spots: light brown skin macules
66
Q

phenylketonuria (PKU) is a lack of what

A

phenylalanine hydroxylase enzyme, which leads to elevated levels of phenylalanine (can’t convert it to tyrosine)

67
Q

PKU clinical features

A
  • common in Scandinavian
  • impaired brain development
  • decreased hair/skin pigmentation (tyrosine = precursor of melanin)
68
Q

PKU tx

A

life-long diet restriction

69
Q

PKU dental implications

A
  • potential higher cariogenic diet and erosive supplements
  • headaches, ADD and trouble focusing
70
Q

what are lysosomes critical in

A
  • breakdown of complex molecules (& autophagy)
  • immunity = fuse with phagosomes
  • membrane repair = fusion with plasma membrane
71
Q

lack of lysosomal enzyme leads to what

A
  • accumulation of paritally degraded metabolites (primary storage)
  • defective degradation of organelles (secondary storage)
    —-> old mitochondria —> triggers free rad production and apoptosis
72
Q

cell dysfunction is made worse by what

A

macrophage activation and cytokine release

73
Q

general features of lysosomal storage diseases

A
  • autosomal recessive
  • ashkenzai jews
  • typically fatal in childhood
  • frequent CNS involvement
74
Q

examples of lysosomal storage diseases

A
  • glycogenoses
  • Tay-Sachs disease
  • Niemann-Pick disease
  • Gaucher disease
  • mucopolysaccharidoses
75
Q

clinical features of glycogen storage disease

A
  • liver enlargement
  • m weakness
76
Q

examples of mucopolysaccharidoses

A

hunter syndrome
hurler syndrome

77
Q

mucopolysaccharidoses causes what

A

caridac problems, mental retardation

78
Q

define penetrance

A

proportion of individuals with a mutation that exhibit clinical symptoms

79
Q

define expressivity

A

how severe or mild the symptoms are

80
Q

penetrance and expressivity are features of which mutations

A

triple repeat mutations

81
Q

define anticipation of triple repeat mutations

A

timing of disease is sooner and more severe from gen to gen

82
Q

two examples of triple repeat mutations

A

huntington disease
fragile x syndrome

83
Q

huntington is what kind of disease

A

autosomal dominant

84
Q

huntington causes what to happen

A

misfolded proteins in the brain = uncontrolled movement (chorea), decreased cognition

85
Q

fragile x syndrome is what kind of disease

A

x-linked

86
Q

fragile x syndrome causes what to happen

A

moderate to severe retardation, post-pubertal macroorchidism (large testicles)

87
Q

define genetic imprinting

A

epigenetic alteration –> silences a gene on one chromosome so only one is expressed
- if functional allele is deleted, disease occurs

88
Q

define uniparental disomy

A

2 chromosomes from one parent and none from the other

89
Q

what are examples of genomic imprinting and uiparental disomy

A

prader-willi syndrome
angelman syndrome

90
Q

complex multigenic inheritance have to do what for phenotype to be expressed

A

total number of effector alleles needs to exceed a threshold

91
Q

two examples of congenital defects of multigenic disorder

A
  • cleft palate
  • congenital heart defects
92
Q

examples of multigenic diseaese

A
  • type 1 and 2 diabetes
  • hypetension
  • gout
  • cancer
  • glaucoma
  • epilepsy
  • schizophrenia
93
Q

is loss or gain of chromosomal material worse

A

loss is worse

94
Q

down syndrome is trisomy of which chromosome

A

21

95
Q

klinefelter sx is what

A

male with at least two X chromosomes and one or more Y chromosomes

96
Q

clinical features of klinefelter sx

A
  • decreased male traits
  • infertility
  • male breast development (gynecomastia)
97
Q

Turner sx is what

A

female with loss of one X chromosome

98
Q

clinical feature of Turner sx

A
  • slowed growth
  • infertility
  • decreased female secondary sex characteristics
  • cardiovasc. problems –> childhood death
99
Q

dental findings of Turner sx

A

increased caries rate, hypoplasia of crowns and roots

100
Q
A

Pathology Exam 1 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions