儿童单基因肾结石病基因型特点分析

Characteristics of genotype of monogenic nephrolithiasis in Chinese pediatric patients with nephrolithiasis

目的分析单基因肾结石病患儿的基因型特点。方法回顾性分析2016年1月至2020年12月在首都医科大学附属北京友谊医院诊治的56例单基因肾结石病患儿临床资料和基因检测结果,所有患儿均为全外显子测序诊断,分析患儿基因型特点。结果 56例单基因肾结石病患儿中男39例、女17例,平均年龄4岁(5个月~14岁),共发现11种基因存在突变,包括常染色体隐性遗传基因7种,X连锁隐性遗传基因1种,显性和隐性遗传基因3种,其中HOGA1基因突变最为常见(16例,28.6%),其次为AGXT基因(15例,26.8%),SLC3A1基因(6例,10.7%),SLC7A9基因(5例,8.9%)和GRHPR基因(5例,8.9%)。突变类型包括无义突变、移码突变和剪切位点突变等,新发突变14个。AGXT、GRHPR和HOGA1等基因具有突变热点或热点区域,分别为c.815-816insGA和c.33dupC突变、c.864865delTG突变和c.834-834+1突变区域;SLC3A1和SLC7A9基因有9种新发突变,但未发现突变热点或热点区域。结论儿童单基因肾结石病多为常染色体隐性遗传,致病基因中以HOGA1、AGXT、SLC3A1、SLC7A9和GRHPR等基因突变多见;AGXT、GRHPR和HOGA1等基因具有突变热点或热点区域,且突变可能具有种族差异性。

Objective To analyze the genotype characteristics of children with monogenic nephrolithiasis.Methods The clinical data and genetic test results of 56 children with monogenic nephrolithiasis diagnosed and treated in Beijing Friendship Hospital,Capital Medical University from January 2016 to December 2020 were analyzed retrospectively.All pediatric patients were diagnosed by whole exome sequencing,and the genotype characteristics of the children were analyzed.Results Among 56 children with monogenic nephrolithiasis,there were 39 males and 17 females,with an average age of 4 years(range,5 months to 14 years).A total of 11 genes were found to have mutations,including 7 autosomal recessive genes,1 X-linked recessive gene,and 3 genes with both recessive and dominant,of which HOGA1 gene mutation was the most common(16 cases,28.6%),followed by AGXT gene(15 cases,26.8%),SLC3A1 gene(6 cases,10.7%),SLC7A9 gene(5 cases,8.9%)and GRHPR gene(5 cases,8.9%).The mutation types included nonsense mutations,frameshift mutations and splicing mutations,with 14 novel mutations.Genes such as AGXT,GRHPR and HOGA1 have hotspot mutations or hotspot mutation regions,which are c.815-816 insGA and c.33dupC mutation,c.864-865delTG mutation and c.834-834+1 mutation region;SLC3A1 and SLC7A9 genes had 9 novel mutations,but no hotspot mutation or hotspot regions were found.Conclusion Monogenic nephrolithiasis is rare and mostly autosomal recessive in Chinese children,with mutations in the causative genes HOGA1,AGXT,SLC3A1,SLC7A9 and GRHPR.AGXT,GRHPR and HOGA1 genes have hotspot mutations or hotspot mutation regions,and mutations may have ethnic differences.