智力障碍患儿ARX基因起始密码c. 1A>G变异的遗传学分析

Identification of a c.1A>G initial codon variation of ARX gene in a child with severe mental retardation

目的对1例智力障碍患儿进行基因变异分析,明确其遗传学病因。方法对1例智力障碍患儿进行目标区域捕获测序,将测序结果与GenBank提供的标准序列进行对比,寻找基因序列的变异。对于检出的可能致病性变异,应用Sanger测序法,对患儿双亲进行验证,并分析患儿的临床遗传学特点。结果检测出患儿ARX基因c.1A>G半合子变异;双亲验证后,证实母亲为ARX基因c.1A>G杂合变异携带者,因此患儿的变异遗传自母亲。通过检索公共数据库及本地数据库该变异未收录、也未见文献报道,ARX基因c.1A>G变异为未报道过的新变异,临床意义为“可能致病性变异”。结论AKX基因c.1A>G(pMetl?)变异可能与患儿的智力障碍的发生相关。

Objective To explore the genetic basis for a child featuring severe mental retardation.Methods The child was subjected to target region capture and next generation sequencing.Suspected variants were verified by Sanger sequencing.Results The child was found to harbor a hemizygous c.1A>G(pMetl?)variation of the ARX gene,for which his mother was a heterozygous carrier.The mutation was unreported previously and was predicted to be“ probably pathogenic” by bioinformatic analysis.Conclusion The c.1A>G(pMetl?)variant of the ARX gene may underlie the occurrence of severe mental retardation in this child.