Type 1 collagen synthesis by skin fibroblasts from 17 patients with osteogenesis imperfecta type III.

The aim of this study was to look for osteogenesis imperfecta (O.I.) specific features in collagen synthesised by skin fibroblast cultures obtained from patients with severe progressive deforming O.I. type III. Results from 17 O.I. type III cultures were contrasted with results from 6 relatives, 3 unrelated controls, 6 O.I. type II, 7 O.I. type IV and 7 O.I. type I cultures. Biosynthesised radiolabelled collagen types I and III were extracted and separated by gel electrophoresis as intact alpha chains or as cyanogen bromide digested peptides. Various abnormalities of type I collagen synthesis were detected in cultures from 13/17 O.I. type III patients. In conclusion, synthesised collagen abnormalities were detected in cells from most O.I. type III patients studied and were O.I.-specific, not O.I. type III-specific at the individual level. However, the frequency of detection of these features was partially specific to the O.I. type III phenotype.