A Novel COMP Mutated Allele Identified in a Chinese Family with Pseudoachondroplasia

Pseudoachondroplasia (PSACH) is an autosomal dominant skeletal dysplasia with an estimated incidence of ~1/60000 that is characterized by disproportionate short stature, brachydactyly, joint laxity, and early-onset osteoarthritis. COMP encodes the cartilage oligomeric matrix protein, which is expressed predominantly in the extracellular matrix (ECM) surrounding the cells that make up cartilage, ligaments, and tendons. Mutations in COMP are known to give rise to PSACH. In this study, we identified a novel nucleotide mutation (NM_000095.2: c.1317C>G, p.D439E) in COMP responsible for PSACH in a Chinese family by employing whole-exome sequencing (WES) and built the structure model of the mutant protein to clarify its pathogenicity. The novel mutation cosegregated with the affected individuals. Our study expands the spectrum of COMP mutations and further provides additional genetic testing information for other PSACH patients.