ADA*2 allele of the adenosine deaminase gene may protect against coronary artery disease.

BACKGROUND/AIMS: The common G22A polymorphism in the adenosine deaminase (ADA) gene leads to substitution Asp8Asn. The lower activity of the enzyme encoded by A22 (ADA*2) allele may increase tissue concentrations of adenosine, a potent cardioprotective agent. In a case-control study, we investigated the association between ADA polymorphism and coronary artery disease (CAD).

METHODS

A hundred and seventy-one CAD patients from the north-western part of Poland and 200 consecutive newborns from the same population were genotyped by PCR-RFLP.

RESULTS

Twenty-five ADA*1/2 heterozygotes (12.5%) and 2 ADA2/*2 homozygotes (1%) were found in the control group, while only 10 *1/*2 heterozygotes (5.9%) and no 2/2 homozygotes were found in the CAD group. Frequencies of ADA2 carriers (5.9% vs. 13.5%, p = 0.015) and ADA2 allele (2.9% vs. 7.3%, p = 0.0083) were lower in CAD patients than in controls. Among CAD patients, a significantly lower proportion of *2 allele carriers was treated with diuretics and ACE inhibitors when compared to *1/*1 wild-type homozygotes.

CONCLUSION

ADA*2 allele may decrease genetic susceptibility to CAD. ADA should be added to the list of candidate genes modifying the risk of cardiovascular diseases.