The angiotensin-I converting enzyme (ACE) gene I/D polymorphism and ACE levels in Pima Indians.

An insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE) gene is associated with plasma ACE levels in white populations. The occurrence of the I/D polymorphism and relationship to ACE levels was examined in a Pima Indian group (n = 305). The frequency of the D allele was lower in Pimas than whites (0.29 v 0.52 respectively). ACE levels were significantly associated with genotype in both groups (p = 0.0001), which accounted for 6.5% of the variation in ACE levels in Pimas and 18% in whites. The association of the I/D polymorphism with ACE levels confirms the relationship across ethnic groups. The low frequency of the D allele in Pima Indians shows that ethnic differences should be accounted for when studying the ACE gene.