Open AccessTandem duplication within a type II collagen gene (COL2A1) exon in an individual with spondyloepiphyseal dysplasia.
Author(s) -
George E. Tiller,
David L. Rimoin,
Louann W. Murray,
Daniel H. Cohn
Publication year - 1990
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.87.10.3889
Subject(s) - gene duplication , exon , genetics , biology , tandem exon duplication , gene , mutation , tandem repeat , point mutation , microbiology and biotechnology , genome
We have characterized a mutation in the type II collagen gene (COL2A1) that produces a form of spondyloepiphyseal dysplasia. The mutation is an internal tandem duplication of 45 base pairs within exon 48 and results in the addition of 15 amino acids to the triple-helical domain of the alpha 1 chains of type II collagen derived from the abnormal allele. Although the repeating (Gly-Xaa-Yaa)n motif that characterizes the triple-helical domain is preserved, type II collagen derived from cartilage of the affected individual contains a population with excessive posttranslational modification, consistent with a disruption in triple-helix structure. The mutation is not carried by either parent, indicating that the phenotype in the affected individual is due to a new dominant mutation. DNA sequence homology in the area of the duplication suggests that the mutation may have arisen by unequal crossover between related sequences, a proposed mechanism in the evolution and diversification of the collagen gene family.