Slow progressive FSGS associated with an F392L WT1 mutation.

Constitutional missense mutations in the WT1 gene are usually associated with the Denys-Drash syndrome, characterized by a rapid progressive nephropathy, male pseudohermaphroditism, and an increased risk for Wilms tumor. We report here a patient with scrotal hypospadias and a slow progressive nephropathy due to focal and segmental glomerulosclerosis. WT1 mutation analysis revealed a constitutional missense mutation in exon 9 resulting in an exchange F392L. This mutation has previously been reported by others in a patient with a similar mild course of nephropathy. In contrast, a mutation in the corresponding codon of exon 8 (F364L) was previously found by us in a patient with a very rapid progression to end-stage renal disease. Whether the position of a mutation may influence the course of the nephropathy must be evaluated in a larger patient cohort. The individual tumor risk for this alteration cannot be given at present because neither of the two patients has shown evidence of a Wilms tumor or a gonadoblastoma to date.