Medullary cystic disease of the kidney: its occurrence in two siblings

Summary Two cases of medullary cystic disease of the kidney in two siblings are presented. In both siblings there was an insidious onset of azotaemia and anaemia at an early age. The urinalyses were normal except for a trace of proteinuria and persistent low specific gravity. The kidneys were small by radiological studies and this was proved at necropsy. The gross microscopic appearances of the kidneys were consistent with medullary cystic disease. The literature on this subject and current views on the similarities between familial juvenile nephronophthisis and this condition are discussed.