is a condition that affects the kidneys and genitalia. Kidney disease typically begins in the first few months of life, often leading to kidney failure in childhood. In addition, up to 90 percent of people with this condition develop a rare form of kidney cancer known as Wilms tumor. Males with Denys-Drash syndrome have gonadal dysgenesis, a condition in which the external genitalia do not look clearly male or clearly female (ambiguous genitalia) or the genitalia appear to be completely female. The testes are also undescended, meaning that they remain in the pelvis, abdomen, or groin. Affected females usually have normal genitalia. For this reason, females with this condition may be diagnosed with isolated nephrotic syndrome. Denys-Drash syndrome is caused by mutations in the WT1 gene. This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. However, most cases result from new mutations in the gene and occur in people with no history of the disorder in their family. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.