Genetics-Bemis

Question 1

Penetrance

Answer 1

The percentage of individuals with a given genotype who exhibit the phenotype associated with that genotype.

Question 2

Describe the phenotype, possible genotype and mode of inheritance of familial hypercholesterolemia (also called hyperlipidemia type IIA).

Answer 2

a. Autosomal dominant
b. Homozygotes have severe cardiovascular disease
c. Heterozygotes have less severe problems
d. Possible mutations
i. LDLR receptor gene
ii. APOB (apolipoprotein B) gene mutated
iii. Pro-protein convertase subtillsin/kexin 9 (PCSK9) gene mutated

Question 3

Candidate Gene Approach

Answer 3

typically a case control approach that searches for a statistical associated between specific genetic variant and a disease of interest

Question 4

Linkage Analysis

Answer 4

a family-based approach in which the genome is scanned for pre-specified DNA markers that are known to be highly variable (microsatellites). Regions that are found more commonly in the disease members of the family are said to be linked to the causative gene, which is then pursued with fine mapping

Question 5

GWAS (Genome wide association study)

Answer 5

A novel approach in which SNPs are genotyped across the entire genome in subjects with and without a dive disease. SNPs that differ in frequency between cases in comparison with controls are “associated” with disease.

Question 6

Locus Heterogeneity

What condition is associated with this?

Answer 6

A single disorder, trait, or pattern of traits caused by mutations in multiple genes at different chromosomal loci

Basically, many genes control 1 disease. so it’s tough to know which gene is actually responsible for a given disease.

CHF

Question 7

“Variance in alleles”

What disorder?

Answer 7

Essentially the same as locus heterogeneity–multiple alleles of different genes can contribute to a single disorder (HTN)