Genetics: Analysis and Principles 4th Edition by Robert Brooker

Exercise 9

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