Studies on collagen metabolism in the Marfan syndrome

The pattern of collagen metabolism was studied in nine fibroblast cultures from Marfan patients. The cellular synthesis of collagen and non-collagenous proteins was significantly increased, whereas secretion and degradation remained unchanged. Other steps of post-translational processing such as hydroxylation of prolyl or lysyl residues, affecting triple helix stability, were found to be normal. Furthermore, peptide mapping of isolated a 1(I), a 2(I) and a 1(III) gave no evidence for structural defects. Hence, our study would support the notion that defects other than those affecting collagen type I or III metabolism must represent the molecular basis of the Marfan syndrome.