Fatty acid desaturase genetic variations in heart failure and cardiovascular disease

Omega (ω)-3 polyunsaturated fatty acids (PUFAs) have gained prominence for their putative cardioprotective functions. However, the data supporting their beneficial effects has been inconsistent. One possible explanation is that there is genetic variability in the fatty acid desaturase (FADS) 1 and 2 genes (encoding the delta-5 and delta-6 desaturase enzymes, respectively) which may influence PUFA levels. These enzymes are responsible for adding a double bond to the tails of ω−3 fatty acids and constitute the rate limiting step in ω−3 PUFA processing. As a result, they appear to have downstream effects on circulating blood levels of ω−3 PUFAs. In this review, we discuss commonly reported genetic variants within the FADS genes that have been associated with cardiovascular disease and/or cardiovascular risk factors. In addition, we summarize the data assessing the association between these genetic variants and the incidence of cardiovascular disease and cardiovascular risk factors, desaturase expression, circulating blood levels of ω−3 PUFAs, and the effect of diet and ω−3 dietary supplements on circulating levels.