Indeed, ARA levels are controlled by FADS1 (delta 5-desaturation) FADS2 (delta 6-desaturation) gene cluster and a variation of approx. 28% for ARA levels can be explained by the single-nucleotide polymorphism (SNP) of the 5-locus and 11-locus haplotypes, possibly increasing the risk for complex diseases (i.e., immunological and neurological diseases) [33]. This evidence concerns the gene FADS2 and nervous system disorder.