CBCL2: Medical Genetics Chapter 9

Question 1

Modifier Genes

Answer 1

Genes that are not associated with disease origin, but once disease is present these genes modify the severity

Question 2

Multipoint linkage

Answer 2

multiple densely spaced markers of disease on a genome

–>evidenced through analyzing genomes of siblings affected with same complex disease

Question 3

Associated

Answer 3

when two alleles OR two phenotypes occur together in a population in a nonrandom manner with statistical significance they are associated

• ->does NOT prove that one causes the other
• ->evaluated by relative risk

Question 4

RET mutations in conjunction with what cause what disease?

Answer 4

RET with NRTN, SOX10, EDN, and GDNF cause

Hirschsprung Disease: Congenital intestinal aganlionosis

Question 5

NTD associated with what primary gene?

Diff

Answer 5

MTHFR

c to t mutation causing ala22val substitution

Question 6

2 different severities /likelihoods of NTD by MTHFR mutations?

Answer 6

most severe:

1. MTHFR c to t mutation
   - ->ala22val
2. MTHFR
   - ->arg653gln

Question 7

30% ptns with Type 1 diabetes are heterozygous for:

Answer 7

HLA-DQ2/DQ8

Question 8

Rare single Gene mutation responsible for Type 2 Diabetes:

Answer 8

GCK

Question 9

Types 1 and 3 MODY (type 2) caused by mutations in:

Answer 9

HNF4A: steroid hormone an thyroid hormone receptor expressed in liver, kidney, intestine, pancreas

–>which affects HNF1A

Question 10

Alzheimer’s Disease genes:

Answer 10

APP (amyloid plaque precursor)

–>found on chromosome 21

Question 11

Alzheimer’s Disease modifier gene:

Answer 11

APOE e4 allele