Abstract
Familial juvenile hyperuricemic nephropathy (FJHN) is an autosomal dominant disease characterized by hyperuricemia of the underexcretion type, impairment of urinary concentration and tubulointerstitial nephritis leading to chronic renal failure. In 2002, it was revealed that FJHN is caused by mutation of the uromodulin (UMOD) gene located on chromosome 16p11–13. Here, the proband was a 14-year-old boy referred to our hospital because of renal insufficiency (creatinine 1.33 mg/dℓ). His father had been affected by gout and chronic renal failure since the age of 26 years, and treated with peritoneal dialysis since he was 35 years old. Renal biopsy of the proband showed severe tubulointerstitial injury with sclerotic glomeruli. Additionally, he presented with the complications of hyperuricemia (uric acid 9.4 mg/dℓ) of the underexcretion type and impairment of urinary concentration. To confirm the diagnosis, the UMOD gene was analyzed and a heterozygous missense mutation (c.281 G>T [C94F]) in exon 3 of UMOD of both the proband and his father was identified. This mutation has not been reported previously. In conclusion, we report a 14-year-old boy and his father with FJHN due to a novel mutation, highlighting the importance of FJHN as a differential diagnosis in autosomal dominant renal insufficiency.
