5P: Genotype to phenotype

Question 1

Penetrance (P)

Answer 1

The probability of a genotype that will manifest the trait

- P(%)= clinically affected individuals/obligate carriers x100

Question 2

When is penetrance typically variable?

Answer 2

In dominant inheritance -> causes trait to skip generations

Question 3

An example of an autosomal disorder with incomplete penetrance

Answer 3

Polydactylyl (many fingers or toes)

Question 4

Multiple allelism

Answer 4

There are more than three alleles of a gene in a population

only two of them may be in one individual

Question 5

Complex heterozygosity

Answer 5

An individual who has two different mutant alleles at a locus

Question 6

Allelic heterogeneity

Answer 6

Different alleles may cause same (similar) disease

Question 7

Epistasis

Answer 7

• Describes how gene interactions can affect phenotypes

- When two different genes contribute to a single phenotype, those genes are said to be epistatic