Severe osteogenesis imperfecta caused by double glycine substitutions near the amino-terminal triple helical region in COL1A2

Am J Med Genet A. 2015 Jul;167(7):1627-31. doi: 10.1002/ajmg.a.37051. Epub 2015 Apr 9.

Abstract

Most cases of osteogenesis imperfecta (OI) are caused by heterozygous mutations in COL1A1 or COL1A2, the genes encoding the two type I procollagen alpha chains, proα1 (I) and proα2 (I). We report on a unique case of severe OI, a long term survivor of lethal type II OI, rather than progressively deforming type III, due to double substitutions of glycine residues in COL1A2 (p.Gly208Glu and p.Gly235Asp), located on the same allele. To the best of our knowledge, this is the first example of a patient with double COL1A2 glycine substitution mutations on the same allele. We show for the first time that double COL1A2 glycine substitution mutations located near the amino-terminal triple helical region, which individually are likely to result in mild OI, cause severe OI in combination.

Keywords: double mutation; glycine; osteogenesis imperfect.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution / genetics*
  • Base Sequence
  • Collagen Type I / genetics*
  • DNA Mutational Analysis
  • Female
  • Glycine
  • Humans
  • Infant
  • Infant, Newborn
  • Japan
  • Molecular Sequence Data
  • Multiplex Polymerase Chain Reaction
  • Osteogenesis Imperfecta / diagnostic imaging*
  • Osteogenesis Imperfecta / genetics*
  • Radiography

Substances

  • COL1A2 protein, human
  • Collagen Type I
  • Glycine