Clinical analysis of gene mutation in children with steroid-resistant nephrotic syndrome in a single center

Objective To analyze the podocyte gene mutation in children with steroid-resistant nephrotic syndrome (SRNS), and to explore the clinical manifestations and prognosis of children with gene mutation, so as to provide a theoretical basis for the diagnosis and treatment of SRNS gene mutation in children. Methods Twenty-four patients with SRNS diagnosis and ages less than 14 years old were selected from the Pediatric Nephrology Center of First Affiliated Hospital of Sun Yat-Sen University during August 31, 2014 to September 1, 2016.The gene detection was performed through PCR amplification and second DNA general sequencing, in which the target genes were detected in 23 cases with nephrotic panel, and 1 case was sequenced with the exon gene. Results There were 14 cases of male and 10 cases of female in 24 cases of genetic testing.The median age of onset was 4.7 years old.There were 9 cases of simple type, 15 cases of nephritis type.And all the cases were primary steroid-resistant.Within the 20 cases of renal biopsy, there were 5 cases of minimal change disease (MCD), 11 cases of focal segmental glomerulosclerosis(FSGS), and 4 cases of mesangial proliferative glomerulonephritis (MsPGN). In the 24 cases, there were 8 cases of gene mutation.Their age was (3.97±3.61) years old.The ratio of male and female was 1.671.00.The main clinical classification was nephritis type (6/8 cases). The major genes were NPHS2(3 cases), NPHS1(2 cases), INF2(2 cases), MYO1E(1 case). And FSGS was the main pathological type (4 cases). Most of them were no remission or end stage renal disease(ESRD) (6/8 cases), including 2 cases of renal transplantation.The 24 hour urine protein level in the gene mutation group was significantly higher than that in the non-mutation group [195.4 (166.0, 262.4) mg/(kg·d) vs. 85.4 (74.5, 101.3) mg/(kg·d)], and the difference was statistically significant (Z=-3.674, P<0.001). Conclusion The main mutation genes of children with SRNS were NPHS2, NPHS1 and so on.FSGS was the main pathological type.Most of them were no remission or ESRD.The higher of the 24 hour urine protein level, the more possibility of genetic mutation. Key words: Nephrotic syndrome; Steroid-resistance; Gene mutation; Prognosis; Child