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.
Hence, we examined the entire coding region of COL10A1 by direct sequencing of DNA from five unrelated patients with SMD and found a heterozygous missense mutation (Gly595Glu) cosegregating with the disease phenotype in one SMD family.