Pedigree analysis

Question 1

Autosomic recessive disease

Answer 1

Skips generations, shows up with inbreeding

Question 2

Autosomic dominant disease

Answer 2

Every generation, mostly affected are heterozygous, about 50% of progeny of affected parent

Question 3

X-linked recessive disease

Answer 3

Mostly males, no male-to-male inheritance

Question 4

X-linked dominant

Answer 4

2females : 1males, all daughters of affected male

Question 5

Functional consequences of recessive disease

Answer 5

Loss of function: one allele is enough (haplo-sufficient), but losing two leads to a loss of function (lower threshold).

Question 6

Functional consequences of dominant disease

Answer 6

• Gain of function: mutation in regulatory part, novel/enhanced products, products that cannot be switched off;
• Haploinsufficiency: dosage-sensitive genes, one healthy allele is not enough (higher threshold).
• Dominant-negative: the gene/product has an antagonistic role against the wild type gene/product.