Single nucleotide polymorphisms (SNPs) in FADS genes are with race- and ethnic-specific distributions and associated with levels of circulating LC-PUFA [8,9,10], and several SNPs in FADS1/FADS2 have been linked with a risk of overweight and obesity [7,11,12]. The gene discussed is FADS2; the disease is obesity due to melanocortin 4 receptor deficiency.