Marfan syndrome is caused by mutations in which gene encoding a connective tissue glycoprotein?

Marfan syndrome is caused by mutations in which gene encoding a connective tissue glycoprotein?

• A. Elastin
• B. FBN1 (Fibrillin-1)
• C. COL1A1
• D. SMAD2

Answer: (B)

Marfan syndrome stems from mutations in the gene that encodes fibrillin-1, a connective tissue glycoprotein that forms microfibrils in the extracellular matrix and helps organize elastic fibers. Defects in fibrillin-1 disrupt microfibril structure and can alter TGF-β signaling, leading to the characteristic features such as tall stature with arachnodactyly, lens displacement, and dilation of the aortic root. The gene responsible is FBN1. Mutations in elastin, collagen type I, or SMAD signaling components produce different connective tissue disorders, not classic Marfan syndrome.

Marfan syndrome stems from mutations in the gene that encodes fibrillin-1, a connective tissue glycoprotein that forms microfibrils in the extracellular matrix and helps organize elastic fibers. Defects in fibrillin-1 disrupt microfibril structure and can alter TGF-β signaling, leading to the characteristic features such as tall stature with arachnodactyly, lens displacement, and dilation of the aortic root. The gene responsible is FBN1. Mutations in elastin, collagen type I, or SMAD signaling components produce different connective tissue disorders, not classic Marfan syndrome.