一个汉族脊柱-骨骺发育不良伴进行性假性类风湿样骨发育不良家系WISP3基因突变筛查

Identification of a novel mutation in WISP3 gene in a Chinese family with spondyloepiphyseal dysplasia tarda associated with progressive pseudorheumatoid dysplasia

目的:观察常染色体隐性遗传病脊柱-骨骺发育不良伴进行性假性类风湿样骨发育不良(PPD)患者的临床特征及影像学表现,并筛查致病基因WISP3的突变类型。方法:采用聚合酶链反应(PCR)和基因组DNA直接测序技术,检测一个非近亲婚配PPD家系4名家庭成员外周血标本中的WISP3基因编码区DNA序列,同时选择100名健康志愿者进行该位点突变检测。结果:该家系中先证者的WISP3基因存在一个新的纯合突变p.Glu243AspfsX13,表现为第5外显子缺失7个碱基(GAAAAGA)。该突变导致243位密码子编码谷氨酰胺变为编码天冬酰胺,其后因产生移码突变而使终止密码子提前产生,氨基酸编码终止在p.256位。先证者的父亲、母亲和姐姐均为该突变杂合子。同时,在100名健康志愿者中进行该基因突变检测,均未发现上述突变。结论:①p.Glu243AspfsX13纯合突变为导致该疾病的一个新突变;②WISP3基因的p.Glu243AspfsX13突变是导致我国汉族人PPD发生的一种突变类型。

Objective To characterize the clinical manifestations and features of spondyloepiphyseal dysplasia tarda associated with progressive pseudorheumatoid dysplasia（PPD） and screen the mutation of the disease causing gene WISP3.Methods One Chinese Han nationality family,including 4 individuals,and 100 control healthy donors were recruited,and genomic DNA was extracted and defined.PPD was diagnosed based on clinical manifestations,physical examination,characteristics of their bones on X-ray and laboratory results.All 5 exons and their exon-intron boundaries of the WISP3 gene were amplified by polymerase chain reaction（PCR） and sequenced directly.Results The proband（11 years old boy） was identified carrying a novel mutation（p.Glu243AspfsX13）.This mutation resulted in a subsequent change of the glutamine codon to asparagine codon and truncation at p.256.Father,mother and sister of the proband were heterozygotes,and p.Glu243AspfsX13 mutation was not found in all the 100 normal controls.Conclusions Our study suggests that the novel p.Glu243AspfsX13 mutation in exon 5 of WISP3 gene is responsible for the PPD in Chinese patients.