exam 2 review Flashcards
exam 2
1
Q
Turner syndrome usually ends in
A
miscarriage
2
Q
most common autosomal aneuploidy leading to miscarriage
A
Trisomy 16
3
Q
Scalp defects (cutis aplasia), microcephaly, micropthalmia, holosencephaly, cleft lip, and palate
- renal anomalies
- polydactyly
- CHD
A
Patau
4
Q
small size, microcephaly, congenital heart defects, overlapping fingers, rocker bottom feet
A
Edwards
5
Q
Flat facial profile, upslanted palebral fissures, anomalous ears, nuchal ckin fold, single palmar crease, clinodactyly, hypotonia, hyperflexibility of joints
A
Down syndrome: newborn features s
6
Q
Lymphedema in infancy, bicuspid aortic valve, coarctation of aorta, short stature, gonadal regression, horseshoe kidney, cubitus valgus elbow, low posterior hairline, webbed neck, widely-spaced hypoplastic nipples
A
turner syndrome
7
Q
tall- statrue, long limbs, learning disability, gynecomastia, small testicles, infertility due to hypogonadism w/ oligospermia/azoospermia
A
Klinefelter
8
Q
47, XXY
A
Klinefelter
9
Q
45, X
A
turner
10
Q
47, xx+21
A
trisomy 21- down
11
Q
47,XX+18
A
trisomy 18- edwards
12
Q
47,xx+13
A
trisomy+13
13
Q
M1 Block
A
heterodisomy
14
Q
M2 block
A
isodisomy
15
Q
loss of material
A
deletion
16
Q
gain of material
A
duplication
17
Q
alteration w/in a chromosome
A
inversion
18
Q
exchange of material between two or more chromosome
A
translocation
19
Q
hypotonia, intellectual disability, hyperphagia (pathological eating)
A
Prader-willi
20
Q
lack of paternal allele expression
A
Prader-Willi
21
Q
severe intellectual disability, movement disorder, seizures
A
angelman
22
Q
lack of expression of maternal allele
A
angleman
23
Q
robertsonian translocations chromosomes
A
13,14,15,21,22
24
Q
results in loss of non-critical genes in the short arm regions of the chromosomes involved
A
robertsonian translocations
25
46,xy,t(1;8)(p22;q24)
balanced
26
46,xx,der(8)t(1;8)(p22;q24)
unbalanced
27
45,xx,der(13;14)(q10;q10)
robertsonian
28
used to confirm clinical dx such as:
- trisomy 21
- large changes
- balanced translocations
karyotype analysis
29
use for quick answer to specific questions:
- microdeletion syndrome
- recurrent acquired translocations
- recurrent acquired numerical changes
FISH analysis
30
a single nucleotide base changed
point mutations
31
replace one aa with another
missense mutation
32
properties of an aa remain the same
conservative
33
properties of the aa are different
non-conservative
34
create a premature stop codon
non-sense mutations
35
same aa produced despite difference in DNA sequence
silent mutations
36
absence of a portion of DNA sequence (usually in coding DNA or regulatory sequences)
Deletions
37
large deletions often result in the loss of multiple _______ genes
contiguous
38
In deletions, size can vary ____ base pair to millions of base pairs and possibly less damaging if in multiples ____bp
In deletions, size can vary 1 base pair to millions of base pairs and possibly less damaging if in multiples 3 bp
39
a constellation of findings due to a specific deletion that encompasses several genes
microdeletion
40
microdeletion is not visible in
karyotype
41
williams
microdeletion
42
type of insertion due to repeated regions of DNA, often whole genes
duplications
43
______ of PMP22 on chromosome 17 causes Charcot-Marie-Tooth disease
duplication
44
Duplication may be in ____ or ______ elsewhere in the genome and can cause ___________
Duplication may be in tandem or sited elsewhere in the genome and can cause microduplication
45
mutations that result in extra DNA-sequence w/in the coding sequence of a gene
insertion
46
insertions, range from ___ base pair to _____ of base pairs
insertions, range from 1 base pair to million of base pairs
47
some forms of crohn's disease are associated with an
insertion mutation
48
outcome is frequently a stop codon, resulting in truncated polypeptide
frameshift mutations
49
frameshift mutation can result from (3)
1. deletions
2. insertions
3. splicing errors
50
affect binding of RNA polymerase to promoter site
promoter mutation
51
promoter mut., can result in reduced production of _______ and decreased production of a ______
promoter mut., can result in reduced production of mRNA and decreased production of a protein
52
Dyskeratosis congenita which causes premature aging and bone marrow disease
promoter mutations
53
loss of function (3)
1. null mutations
2. haploinsufficiency
3. Dominant Negative
54
requires a very specific mutation
Gain of function
55
Classic AR (usually enzyme deficiencies)
null mutations
56
AD/incomplete dominance
haploinsufficiency
57
50% function is sufficient-carriers are healthy
loss of function- AR
58
low density lipoprotein receptor
familial hypercholesterolemia
59
familial hypercholesterolemia example of
haploinsufficiency
60
one mutated allele of LDLR=somewhat elevated cholesterol levels with increased risk for heart disease
haploisufficiency- AD
61
Two mutated alleles of LDLR=very elevated cholesterol levels and early arteriosclerosis w/visible deposits of cholesterol in the skin, eyelids, and cornea
haploisufficiency- AR
62
only one mutant gene is necessary (AD); causes new/gain of function of the protein product
gain of function-AD
63
Achondroplasia
Gain of function
64
A FGFR3 mut., receptor is stuck in the "on" position, which prevents chondrocyte proliferation and short bones
gain of function
65
use when looking for large deletions
multiple ligation-dependent probe amplification [MLPA]
66
use when phenotype of patient consistent w/ known methylation disorder
methylation analysis
67
use to screen when majority of cases have one of a limited number of mutations and may be used for common mutations or ethnicity specific mutations
Allele Specific Oligonucleotide (ASO) analysis
68
All of these are point in:
- confirmation of a clinical dx.
- presymptomatic dx.
- preimpantation and prenatal dx.
- Genotype- phenotype correlation
benefits of DNA based testing
69
All of these are point in:
- genetic heterogeneity
- allelic disorder
- variable expression
- non-partenity
- concerns regarding genetic discrimination
challenges of DNA based testing
70
colorectal cancer- HNPCC
lynch syndrom
71
gene mutation is inherited in family; significantly increased cancer risk
hereditary
72
multiple genes & environmental factors may be involved; some increase in cancer risk
familial
73
cancer occurs by chance or related to environmental factors; general population cancer risk
sporadic
74
two acquired mutations
sporadic cancer
75
one inherited, one acquired mutation
hereditary cancer
76
restrain cell growth
tumor suppressor genes
77
maintain correct DNA sequences
mismatch repair genes
78
tumor suppressor genes (4)
1. Rb
2. NF1
3. p53
4. APC
79
mismatch repair genes (3)
1. MLH1
2. MSH2
3. MSH6
80
which has a better survival rate Patau or edwards?
Edwards
81
example of a cancer that shows balanced translocation
Philadelphia
82
high arch
charcot-Marie-tooth disease
83
cGH array:
red=more of the patient DNA
duplication
84
cGH array:
green= more of control of DNA
deletion
85
single nucleotide polymorphisms
SNPs
86
SNPs is important to realize that
we dont expect the function to be wrong just different
87
a single somatic gene mutation can cause cancer
gain of function
88
growth and transcription factors
gain of function
89
Oncogenes (3)
1. RET
2. BCR-ABL
3. HRAS
90
costello syndrome
HRAS
91
chronic myeloid leukemia, acute lymphocytic leukemia
BCR-ABL
92
lung, multiple endocrine neoplasia
RET
93
higher cancer risk is inherited as an
autosomal dominant trait
94
one inherited and one inherited mutation
hereditary cancer
95
breast, sarcomas, leukemia, and brain
Tp53
96
breast, pancreatic and ovarian
BRCA 1/2
97
stomach, colon, ovary, uterine/endometrial
HNPCC
98
SNP array we expect _______ and to have ___ copies at eahc position
we should expect heterozygosity and two copies at each position
99
SNPs are generally inherited as ______ and SNP can differ in __________
SNPs are generally inherited as mendelian and SNP can differ in frequency
100
Both SNP arrays and cGH arrays reports on amount of DNA, with ________ being more easily recognized
Both SNP array and cGH arrays reports on amount of DNA, with deletions being more easily recognized
101
SNP array can identify loss of __________ or ___________ but can only identify __________ not ____________
SNP array can identify loss of heterozygosity or uniparental disomy but can only identify isodisomy not heterodisomy
102
limitations of array (3)
1. may not detect low lwevel mosaicism
2. only look at quantity, not location
3. can not detect, translocations/inversions
