Early Onset Renal Failure in Congenital Nephrotic Syndrome associated with Congenital Diaphragmatic Hernia by WT1 Gene Mutation

We experienced a female neonate with congenital nephrotic syndrome (CNS) associated with congenital diaphragmatic hernia (CDH). Because of the rare combination of two conditions, we report this case with literature review. CDH was found immediately after birth and emergency operation was done for hernia repair. But on the next day, generalized edema and oliguria(0.59 mL/kg/hour) was found and her blood chemistry showed hypoalbuminemia (1.6 g/dL), increased BUN (27.7 mg/dL) and serum creatinine( 1.8 mg/dL) along with heavy proteinuria (4+). We started albumin infusion with a bolus of intravenous furosemide. We suspected the neonate had congenital nephrotic syndrome and her 24hr urine protein was 1,816 mg/day. In spite of immunosuppressive therapy, the nephrotic syndrome and renal failure progressed. We started peritoneal dialysis on the day of life 22 but it was not satisfactory. She was complicated by intracranial hemorrhage and multi-organ failure and expired at 34 days of age. Kidney necropsy was performed which showed diffuse mesangial sclerosis (DMS). Her chromosome study revealed 46, XX and her gene study revealed a heterozygous missense mutation, Arg366His, in Wilms tumor suppressor gene (WT1). This case deserves attention on account of the 4th case of CNS with CDH revealing the Arg366His mutation in the WT1 gene andG the 1st case of early onset renal failure without male pseudohermaphroditism and Wilms tumor with CNS, CDH and the Arg366His mutation in the WT1 gene. So, this report gives support to the hypothesis that Arg366His mutation in the WT1 gene can result in CNS and CDH.

Two Cases of Isolated Diffuse Mesangial Sclerosis with WT1 Mutations

Here we report two cases of isolated diffuse mesangial sclerosis (IDMS) with early onset end-stage renal failure. These female patients did not show abnormalities of the gonads or external genitalia. Direct sequencing of WT1 PCR products from genomic DNA identified WT1 mutations in exons 8 (366 Arg>His) and 9 (396 Asp>Tyr). These mutations have been reported previously in association with Denys-Drash syndrome (DDS) with early onset renal failure. Therefore we suggest that, at least in part, IDMS is a variant of DDS and that investigations for the WT1 mutations should be performed in IDMS patients. In cases with identified WT1 mutations, the same attention to tumor development should be required as in DDS patients, and karyotyping and serial abdominal ultrasonograms to evaluate the gonads and kidney are warranted.

A Case of Congenital Nephrotic Syndrome due to Diffuse Mesangial Sclerosis

Diffuse mesangial sclerosis (DMS) is one of the underlying pathology of congenital and infantile nephrotic syndrome. Infants with DMS develop nephrotic syndrome before 2 years of age and progress to end stage renal disease within 3 years of age. The authors experienced a case of isolated DMS in a 4-month-old male infant who had nephrotic syndrome for 1 month. The diagnosis was confirmed on the basis of clinical, laboratory, pathological and molecular genetic findings. This is the 3rd case report of DMS in our country and the 1st case report of isolated DMS confirmed by molecular genetic study.