Osteogenesis imperfecta: cloning of a pro-alpha 2(I) collagen gene with a frameshift mutation. Academic Article uri icon

abstract

  • Osteogenesis imperfecta (OI), a brittle-bone disorder, constitutes a major group of the inherited diseases of connective tissue. We have been studying an autosomal recessive form of OI in which the severely affected patient has inherited two abnormal pro-alpha 2(I) collagen alleles from consanguinous parents. Previously, nuclease S1 mapping was employed to localize a defect in the mRNA coding for the pro-alpha 2(I) collagen carboxyl-propeptide. The mutation prevents incorporation of pro-alpha 2(I) chains into the normal type I procollagen heterotrimer resulting in secretion of only pro-alpha 1(I) homotrimers. Here we report complete characterization of the corresponding region of the altered gene. Polyacrylamide gel electrophoresis and Southern blot hybridization showed a small homozygous deletion in the pro-alpha 2(I) collagen gene of the patient and a heterozygous pattern in both parents. Genomic cloning of the patient's DNA revealed a four nucleotide frameshift deletion in exon 1 near the end of translation which apparently instigates use of a new termination codon four nucleotides 3' to the original site. The mutation identified in this OI patient directly demonstrates the critical role of the carboxyl-propeptides in chain selection and assembly during the biosynthesis of procollagen.

published proceedings

  • J Biol Chem

author list (cited authors)

  • Pihlajaniemi, T., Dickson, L. A., Pope, F. M., Korhonen, V. R., Nicholls, A., Prockop, D. J., & Myers, J. C

citation count

  • 188

complete list of authors

  • Pihlajaniemi, T||Dickson, LA||Pope, FM||Korhonen, VR||Nicholls, A||Prockop, DJ||Myers, JC

publication date

  • November 1984