1例腘窝翼状蹼综合征患儿及家属IRF6基因突变的检测

Detection of IRF6 gene mutation in a child with popliteal ptergium syndrome and the family

目的对收集的腘窝翼状蹼综合征(popliteal ptergium syndrome,PPS)患儿及家属进行临床表现分析,并进行IRF6基因的突变检测,提高对该疾病的认识。方法通过对就诊于2015年哈尔滨医科大学附属第二医院的1例PPS患儿及家属进行调查、临床检查和系谱分析,并总结患儿临床资料。在IRF6基因内设计引物扩增编码区及其邻近剪接内含子序列,经分段PCR和DNA测序对比,检测IRF6基因突变情况。结果收集的PPS家系符合常染色体显性遗传特征,先证者及其母亲均患有唇(腭)裂、双侧腘窝赘肉及外阴发育畸形。患儿及其母亲IRF6基因外显子4发现c.251G>A(编码区第251号核苷酸由G变为A)的杂合核苷酸变异,该变异导致第84号氨基酸由Arg变为His(p.Arg84His),为错义变异。结论发现病例及家属IRF6基因存在突变,在第4外显子发现c.251G>A突变,该错义突变可能是PPS的致病因素,可为基因诊断和遗传咨询提供参考依据。

Objective To analyze the collected clinical manifestations of a case of popliteal ptergium syndrome(PPS)and conduct mutation detection of the IRF6 gene in order to raise awareness of the disease.Methods The child with PPS and the family were investigated,and clinical examinations and pedigree analysis was conducted to summarize the clinical data of the patients.A primer amplification coding region and its adjacent splicing intron sequences were designed in the IRF6 gene,and the mutation of the IRF6 gene was detected by segmented PCR and DNA sequencing comparison.Results The collected PPS pedigrees were in accordance with autosomal dominant genetic characteristics.Both the proband and her mother suffered from cleft lip(palatoschisis),bilateral popliteal ptergium,and developmental malformation of the vulva.The 4th extron on IRF6 gene of the child and her mother was found a hybrid nucleotide variation on c.251G>A(the nucleotide number of the coding region changed from G to A),which caused that the 84th amino acid Arg was changed to His(p.Arg84His),defined as a missense variant.Conclusion The mutation of IRF6 gene is found in the case and the family,and the mutation c.251G>A is found in the 4th extron.The missense mutation may be the pathogenic factor of PPS.It can provide reference basis for gene diagnosis and genetic counseling.