Characterization of point mutations in the collagen COL1A1 and COL1A2 genes causing lethal perinatal osteogenesis imperfecta

Abstract

Type I collagen mutations in a group of patients with lethal perinatal osteogenesis imperfecta were identified in fibroblast RNA by a new method which can detect, by chemical modification and cleavage, single mismatched bases in heteroduplexes formed between mRNA and normal cDNA probes. Control cDNA probes spanning the area of the pro-α1(I) and pro-α2(I) chains likely to contain the mutations were radioactively labeled and used to form heteroduplexes with total patient RNA. Treatment of these heteroduplexes with hydroxylamine followed by cleavage of the cDNA strand at reactive bases by piperidine identified mismatches in the pro-α1(I) cDNA in four patients. In the fifth patient a mismatch wa..