Genetic diagnosis for a Chinese Han family with hereditary multiple osteochondromas

Objective To identify the genetic cause for a Chinese Han family affected with hereditary multiple osteochondromas.Methods Two patients,five unaffected relatives of the family and 100 unrelated healthy controls were collected.The coding sequences and intron/exon boundaries of EXT1 gene were amplified with polymerase chain reaction (PCR) and sequenced.Results A heterozygous c.600G＞A (p.Trp200X) mutation in exon 1 of the EXT1 gene was detected in the patients.The same mutation was not found in unaffected family members and 100 healthy controls.Conclusion The hereditary multiple osteochondromas in the family is caused by a nonsense mutation (p.Trp200X) in the EXT1 gene. Key words: Hereditary multiple exostoses;  EXT1 gene;  Gene mutation