Chapter 25, Problem 9CONQ

Ehler-Danlos syndrome is a rare disorder caused by a mutation in a gene that encodes a protein called collagen (type 3 A1). Collagen is found in the extracellular matrix that plays an important role in the formation of skin, joints, and other connective tissues. People with Ehler-Danlos syndrome have extraordinarily flexible skin and very loose joints. The pedigree below contains several individuals affected with this syndrome, shown with black symbols. Based on this pedigree, does the syndrome appear to follow autosomal recessive, autosomal dominant, X-linked recessive, or X-linked dominant inheritance? Explain your reasoning.