Absence of SLC22A12 gene mutations in Greek Caucasian patients with primary renal hypouricaemia

Abstract

Objective. Primary renal hypouricaemia is a hereditary clinical disorder characterized by increased renal urate clearance due to isolated renal tubular defect of uric acid transport. There have been only a few studies on primary renal hypouricaemia in Caucasian populations. Defects in the SLC22A12 gene, which encodes the renal urate transporter URAT1, have been reported to be related to the disease pathogenesis. This study was undertaken to elucidate whether SLC22A12 gene mutations are responsible for low serum uric acid levels in Greek people. Material and methods. Nine Greek Caucasian subjects with primary renal hypouricaemia were included in the study. All had serum uric acid less than 2.5 mg dL⁻¹ (0.14 mmol L⁻¹), fractional excretion of uric acid more than 10 % and no other known causes of hypouricaemia. Mutation analysis of the SLC22A12 gene was performed. Results. No mutation was found – only the previously reported silent polymorphism 1246T>C (His142His) in exon 2 of the SLC22A12 gene. Conclusions. No previously reported mutation of URAT1 was associated with primary renal hypouricaemia in Greek subjects.

• Hypouricaemia
• renal tubular dysfunction
• SLC22A12 gene analysis
• URAT 1
• urate transport
• uric acid