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Flashcards in Finding diseases / Genetic Testing Deck (40)
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1
Q

What type of study is the most common type of genetic study?

A

candidate gene association study

2
Q

What type of study is best for mendelian traits (uncommon alleles with strong effects)?

A

Genetic linkage

3
Q

What types of study can discover new unknown genes?

A

Genetic linkage, GWAS

4
Q

What happens to recombination if the loci are too close to eachother?

A

loci close = tight linkage = lower crossover freq = lower recombination

5
Q

What happens to recombination if the loci are too far from eachother?

A

loci far= absent linkage = higher crossover freq = higher recombination

6
Q

WAGR

caused by?

A
deletion in Pax6 locus on 11p13
Wilms tumor
Aniridia
Genital malform
Retardation
7
Q

What type of genetic test should be used for WAGR

A

chromosomal analysis

8
Q

Chromosomal analysis can diagnose

A

aneuploidies,

chromosomal: deletions, duplications insertions, rearrangements

9
Q

Chromosomal analysis cannot diagnose

A

simple gene deletions,
pt mut
nucleotide repeats
small: dup insertions, methylation

10
Q

FISH probes cannot diagnose

A
  • deletions, rearrangements not spec. tested for
  • duplications
  • pt mut
  • small del
11
Q

Microarray can diagnose:

A

aneuploids
UNBALANCED chromosomal rearrangements
ch del/dup >200kb

12
Q

Microarray cannot diagnose:

A

del/dup <200kb

balanced ch rearrangements/translocations

13
Q

DNA seq cannot diagnose

A

larger indels, rearrangements

14
Q

What mode of inheritance is cystic fibrosis?

A

Autosomal recessive

15
Q

Cystic fibrosis is genetically homogenous/heterogeneous

A

genetically homogeneous

shows allelic heterogeneity not genetic heterogeneity

16
Q

genetic heterogeneity

A

multiple genes (when mutated) are associated with same phenotype

17
Q

what mode of inheritance is hypertrophic cardiomyopathy

A

autosomal dominant

18
Q

hypertrophic cardiomyopathy shows allelic/genetic heterogeneity

A

both

19
Q

What cofactor would you give for homocystinuria patients

A

pyridoxine

20
Q

Multiple endocrine neoplasia (MEN)
cause?
mode of inheritance?

A

RET mutation

autosomal dominant

21
Q

What substance would you avoid for:

G6PD Deficiency

A
antimalarial drugs
(avoidance)
-you should avoid antimalarial drugs if you are G6PD deficient
22
Q

What substance would you give for:

PKU

A

low phenylalanine diet

dietary restriction

23
Q

What substance would you give for:

congenital hypothyroidism

A

thyroxine

replacement

24
Q

What substance would you give for:

urea cycle deficiency

A

sodium benzoate

diversion

25
Q

What substance would you give for:

hypercholesterolemia

A

statin drugs
(inhibition)

Or

LDL apheresis
(depletion)

26
Q

Fabrys disease

caused by? results in?

A

deficiency in alpha-galactosidase

resulting in accumulation of glycosphingolipids

27
Q

Fabrys disease

phenotype

A
belly button spots
microvascular disease
neuropathy
nephropathy
sweat gland damage
28
Q

2 ways to treat Fabrys disease

A

recombinant enz replacement therapy: alpha-gal
or
chaperone based therapy

29
Q

Mode of inheritance of Fabrys

A

x linked

30
Q

Nonsyndromic deafness

caused by?

A

Mut in GJB2 gene (DFNB1) encoding connexin26

31
Q

What fraction of deafness cases are due to congenital defects? How much of that is due to hereditary/genetic factors?

A

1/2, 3/4(nonsyndromic)

32
Q

Deafness with retinitis pigmentosa indicates:

A

usher syndrome

33
Q

Deafness with thyroid goiter indicates:

A

prendred

34
Q

Deafness with sudden death indicates:

A

jervell and lange nielson (AR) syndrome

35
Q

Deafness with white forelock indicates:

A

waardenburg

36
Q

Deafness with 8th n schwannomas indicates:

A

neurofibromatosis type II

37
Q

Premutation of CGG repeats indicates what?

A
  1. Fragile X associated tremor/ataxia syndrome

2. Premature ovarian failure

38
Q

TNRs are hyper/hypomethylated

A

hypermethylated -> reduced/absent FMRP prot

39
Q

Do premutations of CGG have hypermethylation present?

A

no. Not hypermethylated -> increased FMRP RNA!

40
Q

What substance would you avoid for:

acute intermittent porphyria

A

barbiturates