A Chinese Family with Pseudoachondroplasia Caused by COMP Gene Mutation

Abstract

Pseudoachondroplasia (PSACH; MIM 177170) is a rare disease which was characterized by disproportionate short stature, deformity of the lower limbs, brachydactyly, loose joints, and ligamentous laxity. It is an autosomal dominant osteochondrodysplasia presented in childhood, and usually resolved with age, but osteoarthritis is progressive and severe. Genetic testing using the whole exome sequencing and Sanger sequencing was performed for the patients, a 30-year-old woman and her affected son, who is only 8 years old. A heterozygous mutationin exon 15 of COMP (c.1675G > A, p.Glu559Lys, NM 000095.2) was identified. The Polyphen-2 predicted that the mutation may damage the COMP protein function. This study suggested that the heterozygous mutations in COMP were responsible for PSACH and demonstrated the genotype-phenotype relationship between mutations in COMP and clinical characteristics of PSACH.