一个中国汉族遗传性多发性骨软骨瘤家系的基因诊断

Genetic diagnosis for a Chinese Han family with hereditary multiple osteochondromas

目的确定1个遗传性多发性骨软骨瘤家系的分子病因。方法采集家系中2例患者临床资料、2例患者及5名正常家系成员和家系外100名正常对照的外周血DNA，应用聚合酶链反应扩增EXT1基因的全部外显子及外显子与内含子接头，并对扩增产物进行双向直接测序。结果测序发现患者EXT1基因存在c．600G〉A杂合突变（P．Trp200X），正常家系成员及100名正常对照无此突变。结论EXT1基因P．Trp200X突变是导致这个家系发生骨软骨瘤的原因。

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.（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.