Rs4646994

rs4646994 is one of four SNPs representing perhaps the best studied ACE SNP. It is actually not a single nucleotide polymorphism at all; instead, it is an insertion/deletion of an Alu repetitive element in an intron of the ACE gene. Alleles containing the insertion are called "I" alleles, and "D" alleles lack the repetitive element. The other dbSNP entries all tagging this same single insertion/deletion SNP are:


 * rs1799752
 * rs4340
 * rs13447447

There are numerous association studies reported for these SNPs. Examples:


 * (I;I) homozygotes respond better to Viagra than (D;I) or (D;D) individuals, in a study of 100+ Caucasian men with erectile dysfunction. (OR 3.07, CI: 1.03 - 9.13, p=0.04).


 * (I;I) homozygotes are are higher risk for early-onset psoriasis, with an odds ratio of 1.88 (CI: 1.12-3.15, p=0.016).

could represent a gene modulator of carbohydrate intake in morbidly obese Czech population; the strong significant effect of DD genotype was observed in the phenotypes of extreme obesity with the highest carbohydrate intake.