常染色体显性多囊肾病家系PKD1基因突变分析

Analysis of PKD1 gene mutation in a pedigree affected with autosomal dominant polycystic kidney disease

目的对1个常染色体显性多囊肾病(ADPKD)家系进行临床表型分析和致病基因突变检测。方法本研究先证者因“左上颌骨根尖囊肿”于2017年10月10日在东莞市人民医院住院治疗。通过临床表现、影像检查和生化指标等对先证者确诊。采集家系成员及150名健康对照者外周血,通过高通量测序(NGS)法筛选先证者全外显子组突变基因;应用PCR及Sanger测序验证先证者及其家系成员候选突变基因位点,并进一步筛查健康对照者;应用ExAC、dbSNP、HGMD、1000 genomes、ClinVar、PKDB、Mutation Taster和PhyloP数据库及软件进行突变人群频率和生物信息学分析。结果先证者,男,46岁,高血压,尿潜血阳性,血肌酐升高。B超及CT示双侧多囊肾伴左肾结石,多囊肝。测序显示先证者及其二弟、妹妹、女儿和侄女皆存在PKD1基因c.11017-10C>A杂合剪接突变,且150名健康对照者中均未发现该突变。c.11017-10C>A已被dbSNP、ClinVar、HGMD、PKDB和Mutation Taster数据库收录,有害性预测结果为有害,可能导致产生多囊蛋白1(polycystin1,PC1)截短蛋白。结论在中国人群ADPKD家系发现PKD1致病基因突变c.11017-10C>A,拓展了该基因的突变谱。

Objective To analyze the clinical phenotype and detect the pathogenic gene in a Chinese pedigree with autosomal dominant polycystic kidney disease(ADPKD).Methods The proband of this study was hospitalized in Dongguan City People′s Hospital on October 10,2017,due to"left maxillary apical cyst".Clinical phenotypes were noted,imaging examinations and determination of biochemical indicators were carried out for the clinical diagnosis of the proband.Genomic DNA was extracted from peripheral venous blood.Whole-exome genotyping of the proband was performed with the next generation sequencing technology,and the candidate mutation site of the patient and his family members was verified by PCR and Sanger sequencing technology.The mutation site was further screened in 150 unrelated healthy Chinese controls.Mutation frequency within human populations and bioinformatics analysis were predicted with softwares including ExAC,dbSNP,HGMD,1000 genomes,ClinVar,PKDB,Mutation Taster and PhyloP.Results The proband,a 46-year-old male,was diagnosed with hypertension,positive urine occult blood and elevated blood creatinine.B-ultrasound and CT examinations showed that he had bilateral polycystic kidney with left kidney stones and polycystic liver.The gene analysis showed that the c.11017-10C>A heterozygous splice mutation in PKD1 gene was identified in the proband,his second younger brother,younger sister,daughter and niece,but absent in 150 healthy controls.Bioinformatics analysis showed it has been reported in the dbSNP,ClinVar,HGMD,PKDB and Mutation Taster databases.Some databases predicted it has a harmful function for probably leading to production of a truncated polycystin1(PC1)protein.Conclusion c.11017-10C>A underlies the Chinese ADPKD pedigree and expands mutation spectrum of PKD1.