Report of five novel and one recurrent **COL2A1** mutations with analysis of genotype-phenotype correlation in patients with a lethal type II collagen disorder

Mortier, Geert R.; Weis, MaryAnn; Nuytinck, Lieve; King, Lily M.; Wilkin, Douglas J.; Paepe, De, Anne; Lachman, Ralph S.; Rimoin, David L.; Eyre, David R.; Cohn, Daniel H.

doi:doi:10.1136/JMG.37.4.263

Publication

Title

Report of five novel and one recurrent **COL2A1** mutations with analysis of genotype-phenotype correlation in patients with a lethal type II collagen disorder

Author

Mortier, Geert R.

Abstract

Achondrogenesis II-hypochondrogenesis and severe spondyloepiphyseal dysplasia congenita (SEDC) are lethal forms of dwarfism caused by dominant mutations in the type II collagen gene (COL2A1). To identify the underlying defect in seven cases with this group of conditions, we used the combined strategy of cartilage protein analysis andCOL2A1 mutation analysis. Overmodified type II collagen and the presence of type I collagen was found in the cartilage matrix of all seven cases. Five patients were heterozygous for a nucleotide change that predicted a glycine substitution in the triple helical domain (G313S, G517V, G571A, G910C, G943S). In all five cases, analysis of cartilage type II collagen suggested incorporation of the abnormal α1(II) chain in the extracellular collagen trimers. The G943S mutation has been reported previously in another unrelated patient with a strikingly similar phenotype, illustrating the possible specific effect of the mutation. The radiographically less severely affected patient was heterozygous for a 4 bp deletion in the splice donor site of intron 35, likely to result in aberrant splicing. One case was shown to be heterozygous for a single nucleotide change predicted to result in a T1191N substitution in the carboxy-propeptide of the proα1(II) collagen chain. Study of the clinical, radiographic, and morphological features of the seven cases supports evidence for a phenotypic continuum between achondrogenesis II-hypochondrogenesis and lethal SEDC and suggests a relationship between the amount of type I collagen in the cartilage and the severity of the phenotype.

Language

English

Source (journal)

Journal of medical genetics. - London

Publication

London : 2000

ISSN

0022-2593

Volume/pages

37:4(2000), p. 263-271

ISI

000086453000005