Molecular Insights into the Functional Roles of Variants in the FADS Gene Cluster on Omega-3 Long-Chain...

Omega-3 long-chain polyunsaturated fatty acids (n3-LCPUFAs) have strong triglyceride-lowering and anti-inflammatory properties, and high levels of these fatty acids have been associated with reduced risk of cardiovascular disease. The synthesis of n3-LCPUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and n6-LCPUFA, arachidonic acid, share a common pathway mediated by fatty acid desaturase genes, FADS1 and FADS2. LCPUFA synthesis is regulated by both modifiable and non-modifiable factors. Of particular interest is the role of genetic variants in the FADS gene cluster, which are associated with altered FADS1 and FADS2 expression, as well as LCPUFA levels. However, the specific functional variants and the precise molecular mechanisms by which these variants regulate FADS gene expression remain to be elucidated. Variation in the FADS gene cluster is thought to have arisen through natural selection and changing dietary patterns. Available evidence suggests these variants, either individually or as a haplotype, may alter FADS gene expression by modifying DNA methylation in regulatory regions, as well as microRNA and transcription factor binding sites.

This review explores the current state of knowledge regarding the functional roles of these variants on LCPUFA synthesis and how these new insights will help support precision nutrition strategies aimed at improving an individual's n3-LCPUFA status and health.

Identifying specific functional variants in or near the FADS gene cluster and elucidating the mechanisms by which these variants impact LCPUFA synthesis requires further investigation. However, hypothesis generating in vitro studies have revealed roles for epigenetics, non-coding RNAs, and modification of transcription factor binding sites. This knowledge will generate new insights that will help improve our understanding of the genetic basis underlying LCPUFA synthesis and how this may differ across populations.