Spondylar dysplasia in type X collagenopathy

Background The type X collagen gene (COL10A1) is currently known as the dis ease-causing gene of metaphyseal dysplasia type Schmid (MDS), whereas a mut ation of COL10A1 has been reported to cosegregate with a disease phenotype of mild spondylometaphyseal dysplasia (SMD) in a Japanese family. Objective. To elucidate whether or not spondylar dysplasia is common in pat ients with mutations of COL10A1. Materials and methods. We reevaluated the radiological manifestations in si x patients with mutations of COL10A1, who had been previously reported as h aving MDS. Results. Two of six patients showed mild platyspondyly in infancy and early childhood. In both patients, the spondylar dysplasia tended to normalize w ith age, but mild alterations of the vertebral bodies persisted, even into late childhood. The other radiological manifestations of both patients were identical to those of MDS. Conclusion. Our observation suggests that mild spondylar dysplasia may not be uncommon in MDS.