Question

You have identified a family in which clubfoot is inherited as an autosomal dominant trait; and you find that a mutation in the gene OJSYII gene is the cause in the family.

You tested 24 members of the family for the mutations and find out , of these 12 carry the mutation, but only 7 of them display club foot. What is the penetrance in this family?

Answer 1

Answer:

Based on the given information:

• Clubfoot is inherited as an autosomal dominant trait
• Mutation in gene OJSYII causes clubfoot in the family
• Number of members of the family tested for mutation = 24
• Number of members that are carrier for this mutation (heterozygous) = 12
• Number of members that display clubfoot (homozygous recessive) = 7

Penetrance is the frequency of expression of an allele when it is present in the genotype.

Penetrance in the family = 100*(7/12) = 58.3%