FBN1 and Marfan syndrome: Mutations in FBN1 induced by missense, frameshift, nonsense, splicing errors, or complete deletion have been identified in patients with MFS, and these patients have decreased fibrillin-1 incorporation into the ECM, which disrupts disulfide pairing and proper folding of the proteins, decreases fibrillin-1 secretion and assembly into microfibrils, or increases the susceptibility to proteolysis6,28,29.