Spondylar dysplasia in type X collagenopathy

Background. The type X collagen gene (COL10A1) is currently known as the disease-causing gene of metaphyseal dysplasia type Schmid (MDS), whereas a mutation 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 patients with mutations of COL10A1.¶Materials and methods. We re-evaluated the radiological manifestations in six patients with mutations of COL10A1, who had been previously reported as having MDS.¶Results. Two of six patients showed mild platyspondyly in infancy and early childhood. In both patients, the spondylar dysplasia tended to normalize with 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.