Early diagnosis of WT1 nephropathy and follow up in a Chinese multicenter cohort.

BACKGROUND: WT1 mutations cause a wide spectrum of renal and extrarenal manifestations concerning urogenital development and the development of tumors.

METHODS: We retrospectively collected the information on the genotype and phenotype of WT1 nephropathy from the multicenter registry since 2014 to 2019. All patients were stratified by renal function decline status or by sequence timing. Rapid progressive group was defined as rapidly developing into ERSD within 12 months since disease onset. Early sequencing group was defined as gene mutation identified before ERSD.

RESULTS: Thirty-three (3.5%) cases were identified with a WT1 mutation in patients with steroid resistant nephrotic syndrome (SRNS), proteinuria and chronic kidney disease (CKD) 3-5 stage of unknown origin. ESRD developed in twenty patients at a median age of 4.3 years old. Comparing study between the rapid progressive group (n = 8) and non-rapid progressive group (n = 25) showed no significant difference in age of onset, gender, syndrome phenotype, genotype and proteinuria except for initial estimated glomerular filtration rate (eGFR) (p = 0.021) or sequencing timing (p = 0.003). In multivariable logistic regression analysis, the delayed sequencing was associated with rapid renal function decline, even after adjusting for established clinical factors including syndromic phenotype, genotype, age onset and eGFR at initial stage (p = 0.019). The renal survival analysis did not show a significantly better outcome in early sequencing group than in delayed sequencing group (p > 0.05).

CONCLUSION: Screening for WT1 mutations should be performed in children with Wilms' tumor, proteinuria/SRNS or CKD. Early diagnosis of WT1 nephropathy through clinical and genetic findings is warranted.