Which genetic disorder is associated with a defect in the elastic connective tissue protein called fibrillin?

A) Marfan syndrome
B) Huntington disease
C) sickle cell disease
D) phenylketonuria (PKU)
E) cystic fibrosis (CF)

Marfan syndrome is caused by mutations in the FBN1 gene that codes for fibrillin, a protein that forms microfibrils in connective tissue. The defect in fibrillin leads to a range of symptoms including tall stature, long limbs, heart problems, and weakened connective tissue in the eyes, joints, and other organs. Huntington disease is a genetic disorder that affects the nervous system, while sickle cell disease, PKU, and CF are caused by mutations in different genes and affect different body systems.