Characterization of a type I collagen α2(I) glycine-586 to valine substitution in osteogenesis imperfecta type IV. Detection of the mutation and prenatal diagnosis by a chemical cleavage method

Abstract

A chemical cleavage method for detecting mismatched bases in heteroduplexes formed between patient mRNA and control cDNA probes was employed to identify a single base mutation in a heterozygous case of osteogenesis imperfecta type IV. The parents' fibroblast mRNA did not contain the mutation. The region of the mRNA mismatch was amplified by using the polymerase chain reaction, cloned and sequenced. A point mutation of G to U at base-pair 2162 of the collagen α2(I) mRNA resulted in the substitution of glycine by valine at amino acid position 586 of the helix. This substitution disrupted the critical Gly-Xaa-Yaa repeating unit of the collagen triple helix and resulted in helix destabilization,..