Juvenile nephronophthisis-medullary cystic disease complex: a family study.

Two sisters, eight and six years old, respectively, were admitted to Mackay Memorial Hospital in 1993 with the chief complaints of growth retardation, polyuria and nocturnal enuresis. Poor urinary concentration, sodium wasting, anemia and renal insufficiency were noted during hospitalization. Ultrasonography revealed increased renal echogenicity, loss of corticomedullary differentiation and multiple tiny corticomedullary cysts in both kidneys. Renal histopathology showed mild increase in glomerular mesangial cellularity and matrix, mild focal tubular atrophy with thickening of the tubular basement membrane. Other family members were screened by ultrasonography and found another six patients in two generations of the paternal side. Renal cysts were found in five cases. Three of them had progressively deteriorating renal failure. Five had stable renal function after three years of supportive treatment. Thus, it was concluded that the age of onset does not differentiate medullary cystic disease (MCD) from juvenile nephonophthisis (JN), and that JN and MCD could be considered a clinical complex. The absence of corticomedullary cysts on ultrasonography does not preclude the diagnosis. It is also suggested that any children with clinical symptoms of polyuria, polydipsia, anemia and growth retardation from their early years should be carefully examined, and the family history should be investigated to permit early detection of the disease.