Molecular genetics

Question 1

What is the inheritance pattern Fragile X syndrome and Huntington disease have in common?

Answer 1

dynamic mutations

Question 2

What is the inheritance pattern Prada-Willi syndrome and Angelman syndrome have in common?

Answer 2

Uniparental disomy (error in imprinting)

Question 3

What is the inheritance pattern with bottleneck effect and heteroplasmy?

Answer 3

mitochondrial inheritance

Question 4

What is the disease caused by FMR1 gene mutation?

Answer 4

Fragile X syndrome

Question 5

What are the 3 diseases included in newborn screening in HK? What are their respective sampling method?

Answer 5

hypothyroidism, G6PD deficiency: cord blood
phenylketouria: heel prick test

Question 6

Genomic polymorphisms definition

Answer 6

varation present at >1% frequency in the population

Question 7

What is Interntational HapMap project?

Answer 7

a project to catalog most SNPs accross human genome among different populations

Question 8

What is Genome wide association study?

Answer 8

a research method to identify associations between specific genetic variants and particular diseases

Question 9

How to adjust the significance level for GWAS after multiple tests done?

Answer 9

Bonferroni correction
new significance level = α / N

Question 10

Definition of Hardy-Weinberg equilibrium

Answer 10

• genotype frequencies should remain constant from generation to generation
• genotype frequencies are based on allele frequencies, by the binomial expansion of (p+q)^2

Question 11

Reasons for Hardy-Weinberg disequilibrium

Answer 11

Non-random mating:
- stratification
- assortative mating
- inbreeding / consanguinity
Non-constant allele frequencies:
- new mutation
- selection
- fitness (e.g. medical advancement)
- genetic drift
- migration