Juvenile nephronophthisis and medullary cystic disease--the same disease (report of a large family with medullary cystic disease associated with gout and epilepsy).

A large family with medullary cystic disease is described to show that juvenile nephronophthisis and medullary cystic disease should not be differentiated by age of onset and type of inheritance. The age at diagnosis of six family members with medullary cystic disease ranged from 4-32 years, and age at death from renal failure or commencement of dialysis from 7-48 years. A mother of two children with renal failure in early childhood has histological evidence of medullary cystic disease with normal renal function. We suggest that juvenile nephronophthisis and medullary cystic disease are the same conditions and that the disease be classified as medullary cystic disease, autosomal dominant or recessive form. When undertaking genetic counselling in the parents of children with medullary cystic disease, we suggest that renal biopsy may need to be considered even if their renal function is normal. Three patients presented with gout, and the possibility of an association with medullary cystic disease should be considered when more than one member of a family develops gout. Two patients died of status epilepticus, and epilepsy is probably an added association of medullary cystic disease.