In vitro sulfate turnover in osteogenesis imperfecta congenita and tarda

Sulfate (35SO4(-2)) uptake was studied in confluent skin fibroblasts from three patients with osteogenesis imperfecta "congenita," six patients with osteogenesis imperfecta "tarda," three clinically unaffected relatives of an osteogenesis imperfecta tarda patient, and four controls. Only two of the osteogenesis imperfecta congenita cell strains showed an increased uptake of sulfate, all other cell strains being comparable to the control group. The degradation rate of glycosaminolgycans in mutants as seen by the chase experimentas was comparable to that found in the normal control cell strains. Glucose oxidation was normal in the osteogenesis imperfecta cell strains having an abnormal sulfate uptake. This rules out the possibility of an hypermetabolic state of these cells. These findings do not warrant the use of 35SO4(-2) incorporation in cultured cells as a tool for prenatal diagnosis of osteogenesis imperfecta.