Background: The deletion (D) polymorphism of the gene encoding angiotensin-I converting enzyme has been implicated as a risk factor for progressive renal disease in several conditions. This study was designed to evaluate the association between homozygosity for the D allele and susceptibility to renal scarring in children with vesico-ureteric reflux (VUR).
Methods: Two-hundred-and-six children with VUR (all grades) were recruited into the study. Patients were stratified into two groups according to the presence or absence of renal scarring. One-hundred-and-twelve patients (group 1) had evidence of renal scarring. Ninety-four children had no evidence of renal scarring (group 2). ACE genotypes were determined by polymerase chain reaction (PCR) amplification of genomic DNA samples.
Results: There was no association between the DD polymorphism and the presence of renal scarring. Genotype frequencies in group 1 were: II, 29; ID, 56; and DD, 27; and in group 2 were: II, 12; ID, 52; DD, 30 (P=0.21). Neither was there evidence supporting a 'dominant' D allele. There was no association between the DD genotype and the presence of proteinuria or reduced renal function (P>0.05). Hypertension was seen more frequently in those individuals with the DD genotype, compared with the other two genotypes (P=0.012).
Conclusion: We cannot confirm previous reports that children with vesico-ureteric reflux who are homozygous for the deletion polymorphism of the ACE gene are more susceptible to renal scarring than heterozygotes and II homozygotes.