A novel mutation leading to elongation of the deduced α1(X) chain results in Metaphyseal Chondrodysplasia type Schmid

BackgroundMetaphyseal Chondrodysplasia type Schmid (MCDS) is an autosomal dominant skeletal dysplasia, characterized by coxa vara, bowlegs, short limbs and an expanded growth plate hypertrophic zone of the long bone. Previous studies have shown gene mutation of COL10A1 (collagen X, consisting three a1(X) chain) causing human MCDS. To our knowledge, there has been no COL10A1 mutation leading to elongation of the deduced α1(X) chain reported.MethodA four-generation Chinese family with 11 members affected by MCDS was investigated. Mutation screening of the COL10A1 gene was carried out.ResultsBesides the typical MCDS features, we found an earlier onset age and a more frequently occurred knee joint pain history in the family. The following sequence analysis disclosed a novel frameshift mutation (c.2029delG) of COL10A1, which leads to the elongation of the deduced α1(X) chain by 5 amino acids and 4 amino acids substitution. This mutation was not found in all unaffected available members and 50 healthy controls.ConclusionThis is a first report of a frameshift mutation leading to elongation of the deduced α1(X) chain associated with MCDS.