Real-Time PCR Assay with Fluorescent Hybridization Probes for Exact and Rapid Genotyping of the Angio- tensin-converting Enzyme Gene Insertion/Deletion

The serum angiotensin-converting enzyme (ACE) concen-tration depends on the ACE gene insertion/deletion (I/D) polymorphism. This insertion is a 287-bp-long alu repeti-tive sequence localized in intron 16 of the gene (1). The D/D genotype is associated with a higher serum ACE concentration, and it has been demonstrated that it may be associated with ischemic heart diseases (2–4). We are interested in the role of the ACE D allele in ischemic stroke (5, 6). The PCR method reported by Rigat et al. (1) has been modified several times because of preferential amplifica-tion of the D allele. In the past, I/D heterozygotes had been mistyped as D/D homozygotes; the extent of this misclassification has been estimated at;5 % (2, 7, 8). Some of the modified techniques are listed below