Familial juvenile hyperuricemic nephropathy is an autosomal dominant disease characterized by progressive renal disease and hyperuricemia or gout, affecting young people of either sex equally. There are two biochemical markers of this disorder. The first is hyperuricemia disproportionate to the degree of renal dysfunction; the second is a grossly reduced clearance of uric acid relative to creatinine, dispropotionate to age, sex and degree of renal failure. We experienced 2 family members with hyperuricemia. One family member, a 13-year-old girl who had suffered from tophaceous gout and chronic renal failure. Her younger brother also had hyperuricemia and moderately reduced renal function. Their urinary excretion fractions of uric acid($FE_{uric;acid}$) were reduced and renal biopsy specimens showed interstitial fibrosis with tubular atrophy and interstitial urate crystal deposition. We have treated these two patients with allopurinol but we have done renal transplantation because she progressed to end stage renal disease at 16 year old age.