Association of angiotensin converting enzyme and angiotensin type 2 receptor gene polymorphisms with renal damage in posterior urethral valves.

Objective: To examine the association with renal damage in patients with posterior urethral valves (PUV) of two renin-angiotensin system gene polymorphisms: angiotensin converting enzyme insertion/deletion (ACE I/D) and angiotensin type 2 receptor (AT2R A1332G), PATIENTS AND METHODS: In 120 patients with PUV, after stabilization, transurethral fulguration or a Blocksom vesicostomy was performed. Records were reviewed for age at diagnosis, biochemical renal function at diagnosis, results of urine cultures, voiding cystourethrograms, radiologic, sonographic and nuclear medicine scan findings, and follow-up data. ACE I/D genotypes were determined by the polymerase chain reaction using allele specific primers.

Results: The frequency of the ACE DD genotype was significantly higher in patients with chronic kidney disease (P=0.02) and renal scarring (P=0.05). These genotypes were also associated with a statistically higher incidence of vesicoureteral reflux, diurnal incontinence, proteinuria and hypertension. A significantly higher frequency of the AT2R GG genotype was found in PUV patients as compared to healthy unrelated control subjects (P=0.001), and in PUV patients with scarring (P=0.02).

Conclusion: The ACE DD and AT2R GG genotypes are associated with chronic kidney disease and scarring in PUV patients. The GG genotype incidence is higher among PUV patients compared to the control population, and further studies in this area may help understanding of the genetic basis of PUV.