Analysis of clinical phenotype and genotype of PAX2 mutation in Chinese children / 中华肾脏病杂志

ABSTRACT

Objective:To analyze and summarize the clinical, genotypic and pathological characteristics of children with PAX2 gene mutation in China, and to provide information for the monitoring, treatment and prognosis of the disease. Methods:It was a case series analysis study. The clinical data of children with PAX2 gene mutation in Pediatric Nephrology Department, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology from January 2014 to December 2022 were collected, and peripheral blood gene DNA was extracted and sequenced for whole exome sequencing. The clinical, pathological and genotypic characteristics of PAX2 gene variation of children in China were summarized by searching PubMed, Medline, China National Knowledge Infrastructure and Wanfang database and compared with the cases in this single center. Results:Among the 13 children with PAX2 gene mutation, there were 9 males and 4 females, 12 patients with abnormal urine tests, 7 patients with small kidney volume by imaging examination, and 5 patients with renal cysts. The clinical phenotypes were congenital renal and urinary tract malformations in 8 cases, renal coloboma syndrome in 1 case, and hematuria or proteinuria in 3 cases. Five patients underwent renal biopsies, showing focal segmental glomerulosclerosis and C3 glomerulopathy in 1 case, focal segmental glomerulosclerosis in 1 case, thin basement membrane lesion in 1 case, and IgA nephropathy in 2 cases. The genetic testing in 13 children showed 9 de novo mutations and 4 new mutations of c.321G>A, c.213-8C>G, c.63C>A and c.449C>T. There were 2 cases of 76dupG (p.V26Gfs*28) mutant. A total of 51 Chinese children with PAX2 gene mutation were found in the literature search. There were 32 males and 19 females, 8 cases with small kidney volume and 12 cases with renal cysts. The clinical phenotypes were congenital anomalies of kidney and urinary tract in 28 cases, renal coloboma syndrome in 17 cases, and hematuria or proteinuria in 6 cases. Seven patients underwent renal biopsies, including 2 cases with focal segmental glomerulosclerosis, 1 case with minimal lesion, 1 case with mesangial proliferative glomerulonephritis, 1 case with IgA nephropathy, 1 case with membranous nephropathy and a case with focal proliferative sclerosing purpura nephritis combined with glomerular hypertrophy. Thirty-four cases were de novo mutations, and 12 mutations were from the father or mother. The father or mother of 5 children had no clinical manifestations, with normal renal function. There were 11 cases of 76dupG (p.V26Gfs*28) mutant. Conclusions:The clinical phenotypes and genotypes of PAX2 gene variation in Chinese children are diverse. The most common clinical phenotype of PAX2 gene variation is congenital anomalies of kidney and urinary tract. c.76dupG (p.V26Gfs*28) is the most common of PAX2 gene variant.