The angiotensin-converting enzyme (ACE) gene insertion/deletion dimorphism tracks with higher serum ace activities in both younger and older subjects.

BACKGROUND

The absence of a 287 base pair alu sequence in the ACE gene (D allele) is associated with higher ACE levels than its presence (I allele) in adults. We carried out a case-control study of the ACE*I/D dimorphism in relation to circulating ACE activities to evaluate associations between the two variables in adults, compared to younger (18 years or less) individuals.

MATERIALS AND METHODS

Genotypes of the ACEI/D dimorphism were determined on DNA samples from a population of 164 random (unrelated) Emirate nationals, composed of two groups: 112 subjects above 18 years of age (range=20-77 years), and 52 subjects of 18 years or less (range=1-18), and analyzed for putative associations with serum ACE activities. ACEI/D genotypes of the 164 individuals were determined by assays based on polymerase chain reaction. ACE activities were determined on serum samples of these subjects by colorimetric assays.

RESULTS

The D allele was associated with increased ACE values in both adult and younger individuals. Mean ACE activity levels associated with II, ID and DD genotypes, however, were 42%-61% higher in the 18 years and under group of subjects. The ACE*I/D marker accounted for 28% of the variance of the phenomenon determining ACE levels in adults, and for 30% among youngsters.

CONCLUSION

The ACE*I/D dimorphism correlated strongly with circulating ACE activities in both adult and young Emirati subjects, and the corresponding mean ACE activities were significantly higher among the youngsters.