Question

Club foot is one of the most common congenital skeletal abnormalities, with a world-wide incidence of about 1 in 1000 births. Both genetic and nongenetic factors are thought to be responsible for club foot. C.A. Gurnett et al. identified a family in which club foot was inherited as an autosomal dominant trait with reduced penetrance. They discovered a mutation in the PITXI gene that caused club foot in this family. Through DNA testing, they determined that 11 people in the family carried the PITXI mutation, but only 8 of these people had club foot. What is the penetrance of the PITXI mutation in this family

Answer 1

0.727

Step-by-step explanation:

Penetrance can be defined as a measure of the association between a genotype and phenotype. In medical genetics, the penetrance of a mutation leading to the disease state is the proportion of individuals carrying the mutation and showing disease symptoms associated with such mutation. For example, if a mutation leading to the disease state has a 90% of penetrance, it is expected that 9 of each 10 individuals carrying the mutation will develop the disease, while the remaining 10% will not develop the disease. In this case, 8 of each 11 individuals carrying the PITXI mutation show symptoms compatible with the disease, and therefore the penetrance is 8/11 = 0.727 (73%).