TRPC6基因变异致儿童激素耐药型肾病综合征四例并文献复习

Four cases of nephrotic syndrome with TRPC6 gene variations and literature review

目的:探讨TRPC6基因变异致儿童激素耐药型肾病综合征(SRNS)的特征、治疗及预后。方法:回顾性分析2017年1月至2019年12月在上海市儿童医院肾脏风湿科住院的4例(SRNS)且经基因检测为TRPC6变异患儿的临床资料。以“肾病综合征”“TRPC6”“儿童”“nephrotic syndrome”“TRPC6 variation”“child”为检索词,检索建库至2020年8月中国知网数据库、万方数据库、维普数据库及PubMed数据库并进行文献复习。结果:4例SRNS患儿中,男1例、女3例,起病年龄4岁1月龄至12岁2月龄。临床均以浮肿、大量蛋白尿、低蛋白血症起病,4例出现贫血,2例出现继发性甲状旁腺功能亢进,1例肾萎缩。肾脏病理结果示1例为免疫复合物相关性肾炎,3例为局灶节段肾小球硬化。4例患儿病初予足量糖皮质激素治疗4周以上,均为激素耐药,后予糖皮质激素联合免疫抑制剂(如环磷酰胺、钙调神经磷酸酶抑制剂、霉酚酸酯)治疗,症状没有改善。4例患儿2~6个月进展为终末期肾病。全外显子测序显示4例患儿TRPC6基因变异类型分别为c.2684G>T、c.523C>T、c.2678G>A、c.2683C>T,均为新发变异。文献检索纳入中文文献1篇,外文文献9篇,共27例。汇总分析31例(包括本组)病例资料,其中18例错义变异,移码变异、同义变异、剪切变异各1例。起病年龄4月龄至14岁,18例患儿临床表现为大量蛋白尿、低蛋白血症,6例仅表现为蛋白尿,19例患儿病理类型为局灶节段肾小球硬化,IgA肾病、微小病变各2例,塌陷性肾小球病、C1q肾病、免疫复合物相关性肾小球肾炎各1例。18例患儿激素治疗无效,11例钙调神经磷酸酶抑制剂类药物无效。该疾病预后不佳,12例患儿出现肾衰竭,进展至终末期肾病时间为4个月至13.8年。结论:TRPC6基因变异致SRNS的患儿起病年龄较小,病理特征多为局灶节段肾小球硬化,激素及免疫抑制剂治疗多无效,进展迅速预后差。

Objective To investigate the clinical characteristics,treatment and prognosis of TRPC6 variation induced children with steroid-resistant nephrotic syndrome(SRNS).Methods Clinical data of four patients with nephrotic syndrome carrying TRPC6 variations,who were admitted to the Department of Nephrology and Rheumatology,Children′s Hospital of Shanghai from Jan.2017 to Dec.2019,was retrospectively analyzed.The literature search was conducted with"nephrotic syndrome""child"and"TRPC6 variation"as keywords in China National Knowledge Infrastructure(CNKI),Wanfang,Weipu and Pubmed databases until August 2020.Results One of the four cases was male,and the others were female.Onset age ranged from 4-year-1-month to 12-year-2-month.They presented severe proteinuria,hypoalbuminemia or edema as a first symptom.Four patients had anemia,and two patients had secondary hyperparathyroidism,and one patient had renal atrophy.Renal pathology showed that one case was immune complex associated with glomerulonephritis,and the rest were focal segmental glomerular sclerosis(FSGS).They had been initially treated with corticosteroids for more than four weeks,but they had inadequate responses.They were then treated with corticosteroids combined with immunosuppressants(for example,cyclophosphamide,a calcineurin inhibitor,or mycophenolate mofetil).However,the symptoms did not improve.Additionally,four children progressed to end-stage renal disease within 2 to 6 months.Their whole exon gene testing suggested that the variation types of TRPC6 gene were respectively c.2684G>T,c.523C>T,c.2678G>A,c.2683C>T,and all patients had de novo variations in TRPC6.One article in Chinese and 9 articles in English were found,which made up 27 patients.The data of 31 cases(including this group)were analyzed.There were 18 missense variations,one frameshift variation,one synonymous variation and one splicing variation.The onset age was from 4 months age to 14 years old.Among all patients,18 cases had massive proteinuria and hypoproteinemia,6 cases only showed proteinuria.The pathological type of 19 cases were FSGS,2 cases were IgA nephropathy,2 cases were minimal change disease,1 case was collapse glomerulopathy,1 case was C1q nephropathy,and 1 case was immune complex associated glomerulonephritis.Glucocorticoid therapy was ineffective in 18 cases,and calcineurin inhibitor was ineffective in 11 cases.The prognosis of the disease was poor.Renal failure occurred in 12 cases,and the time to end stage renal disease was from 4 months to 13.8 years.Conclusions TRPC6 variation can cause SRNS at a young age.FSGS is the primary pathological type of SRNS causing by TRPC6 variation.Glucocorticoid and immunosuppressive therapy are mostly ineffective.The disease progressed rapidly and the prognosis is poor.