All genetic mutations resulting in familial thoracic aortic aneurysms and dissections (TAAD) appear to be inherited in an autosomal dominant manner. What is the risk that parents, siblings, and offspring of a proband will be affected?

Question

Quizplus · Accepted Answer

In an autosomal dominant inheritance pattern, all offspring have a 50% chance of developing the phenotype, thus B is the correct answer. In an autosomal recessive inheritance pattern, each offspring of two carriers has a 25% chance of being affected, a 50% chance of being a carrier, and a 25% chance of inheriting neither mutant allele. Thus, two-thirds of all clinically unaffected offspring are carriers of the autosomal recessive phenotype. In an X-linked inheritance pattern heterozygous women transmit the mutant gene to 50% of their sons, who are affected, and to 50% of their daughters, who are heterozygotes.

All Genetic Mutations Resulting in Familial Thoracic Aortic Aneurysms and Dissections