<prompt> Mutation in Marfans syndrome is?Collagen ICollagen IVFibrillin IFibrillin II  <response>: Robbins and Cotran pathologic basis of disease South Asia edition. Marfans syndrome results from an inherited defect in an extracellular glycoprotein called fibrillin 1 by loss of structural suppo in microfibril rich connective tissues and excessive activation of TGF- beta signally Ref Robbins 9e pg252 