WT1 exon 10 missense variant in a pediatric patient with focal segmental glomerulosclerosis with embryonal hyperplasia.

A 6-year-old boy was diagnosed with chromosomal abnormalities (48,XYY, + 21[11]/46,XY[19]) at 4 months of age after a physical examination revealed an undescended testis and a dwarf penis. He also had mild renal dysfunction and severe proteinuria, and kidney biopsy at 2 years of age revealed focal segmental glomerulosclerosis. Genetic analysis to investigate suspected WT1 gene abnormalities revealed a novel variant in NM_024426.6:exon10:c.1506 T > A (p.(Asp502Glu)). His kidney function deteriorated rapidly, leading to the induction of peritoneal dialysis at 5 years of age. Although this variant had not been previously reported, bilateral nephrectomy was performed to prevent any progression of the tumor. Histopathology showed all the glomeruli observed within the observation area to be completely sclerotic, while also showing evidence of embryonal hyperplasia. This case was not a hot spot for Denys-Drash syndrome, but it had a similar phenotype and pathology that could have been derived from a WT1 gene abnormality.

Efficacy of oral tolvaptan for severe edema and hyponatremia in a patient with refractory nephrotic syndrome.

Tolvaptan (TLV) is a vasopressin V2 receptor antagonist that increases free water excretion. However, there are few reports of the use of TLV in pediatric patients with nephrotic syndrome (NS). The efficacy of TLV for the management of edema and hyponatremia in a 12-year-old boy with refractory NS is demonstrated. In this patient, refractory NS developed at 5 years of age, and remission was maintained with several immunosuppressive agents. He was admitted to hospital due to relapse with oliguria, edema, hypoalbuminemia, and hyponatremia. Infusion of human albumin and furosemide did not increase his urine volume, and hyponatremia worsened. Administration of TLV increased urine volume and improved his edema and hyponatremia. There were no adverse effects except for slow elevation of the serum sodium level. Serum osmolality increased gradually, and urine osmolality remained at low levels during TLV treatment. Additionally, a decrease in the sum of the urinary sodium and potassium concentrations was useful to predict the response to TLV and to assess the therapeutic effect of TLV as a biomarker for monitoring. TLV is effective for the management of fluid and electrolyte balance in pediatric NS patients. Early administration of TLV is considered a useful therapy for hyponatremia and refractory edema resistant to other diuretics.

Clinical Utility of Highly Purified 10% Liquid Intravenous Immunoglobulin in Kawasaki Disease.

Compared with a 5% intravenous immunoglobulin, a 10% intravenous immunoglobulin as the first-line treatment of Kawasaki disease significantly reduced the fever duration (10 vs 13 hours, P = .022) among the responders, and the interval to adjunctive therapy for nonresponders (47 vs 49 hours, P = .035). There were no severe adverse events.