Genetics: Autosomal dominant (AD)
Caused by a mutation in the FBN1 gene, which affects the production of extracellular glycoprotein fibrillin-1. [PYQ: NEET PG 2024]
Pathophysiology-
• Disrupted Microfibrils
• Excessive TGF-β signaling
Signs and symptoms- Ocular, cardiovascular, skeletal features
Ocular features:
• Bilateral ectopia lentis (dislocation of eye lens)- Superior temporally (Mnemonic: Mast, Ma=Marfan, st = Superior temporal)
Cardiovascular features:
• Aortic dilation or aortic aneurysm, which can lead to aortic dissection (tear in the aorta).
• Mitral valve prolapse
Skeletal features:
• Tall stature
• Arachnodactyly / Spider fingers (abnormally long and slender fingers)
• Spine – Scoliosis, kymphosis
