Analysis of cultured chorionic villi in a case of osteogenesis imperfecta type II: Implications for prenatal diagnosis

We examined collagens produced by cultured cells from skin, chorionic villi, and placental membranes of a 32 week fetus with osteogenesis imperfecta (OI) type II. We observed that skin fibroblasts synthesized two populations of proα1(I) chains of type I procollagen; one population was normal, while the other population had excessive post-translational modification. The thermal stability of helices containing the overmodified chains was reduced 1-2°C. Most significantly, the cells cultured from chorionic villi produced type I collagen chains with the same electrophoretic abnormalities as the skin collagen. This suggests that chorionic villus sampling (CVS) is a means of prenatal diagnosis for families with a previous type II or type IV OI infant.