Improvement in ACE I/D polymorphism detection

The ACE I/D polymorphism has been reported to influence predisposition to cardiovascular disease. Conflicting results in its detection may be due to mistyping of I/D genotypes as D/D genotypes occurring in the traditional genotyping method. In order to resolve mistyping troubles and to permit a rapid and accurate analysis, we performed a stepdown PCR reaction followed by detection using Nanogen technology, and we compared these results with those obtained from traditional genotyping methods, such as conventional and confirmatory PCR. The Nanogen stepdown method showed a 100% sensitivity and 99.6% specificity, when compared with the confirmatory PCR. Our experiments provide evidence that, by using the Nanogen stepdown method, the DD mistyping was markedly decreased, thus representing a useful tool suitable for performing large-scale screening or research.