Hyperuricemia and gout as uncommon manifestation of Papillorenal syndrome in an 18-year-old young man with PAX 2 mutation : A Case report and review of the literature

Hyperuricemia is a metabolic abnormality, either acquired or inherited, characterized by elevated levels of uric acid (UA) in the serum. We are interested in the case report regarding hereditary hyperuricemia. In this case, we are reporting on an 18-year-old man who experienced repeated gout attacks, hyperuricemia, and reduced fraction ejection of uric acid (FEUA). Additionally, he had renal anomalies such as proteinuria and renal hypoplasia and Focal and segmental glomerulosclerosis (FSGS) in the kidney biopsy and eye fundus revealed a bilateral optic disc pit .These findings prompted us to conduct a genetic study on the patient. To our surprise, the DNA sequence analysis did not detect mutations in UMOD or REN, which are commonly associated with familial juvenile hyperuricemic nephropathy (FJHN). Instead, a mutation in the paired box 2 (PAX2) gene was identified which is a very rare entity. We concluded that the patient had papillorenal syndrome (PAPRS) . Hyperuricemia is a rare and uncommon manifestation in patients with PAPRS and PAX2 mutation, and has only been documented in three studies in the literature. The diagnosis of PAPRS is often underestimated and not well-known by clinicians. It exhibits high clinical variability and phenotypic heterogeneity without well-defined diagnostic criteria. The presence of hyperuricemia should prompt consideration of this diagnosis and it should be included in the diagnostic criteria for PAPRS in the future.