Mutant EXT1 in Taiwanese Patients with Multiple Hereditary Exostoses

BACKGROUND: Multiple hereditary exostoses (MHE) is characterized by multiple benign projections of bone capped by cartilage, most numerous in metaphyses of long bones. HME are usually inherited in autosomal dominant mode, chief genes EXT1 and EXT2. METHODS: Two MHE patients were identified from clinic and enrolled in genetic study, complete coding regions of EXT1 and EXT2, including intron/exon boundaries, sequenced via DNA samples drawn from participants. RESULTS: DNA sequencing revealed mutant EXT1 gene in both cases, within which frame-shift mutation c.447delC (p.Ser149fsX156) in exon1 and nonsense mutation c.2034T>G (p.Tyr678X) in exon10, emerged. Neither mutation was detected in control group. CONCLUSIONS: Our results extended the spectrum of EXT1 mutations, revealing similar incidence of EXT1 and EXT2 in Taiwanese MHE patients.