As we known, Variants of FTO gene (such as rs9939609, rs8050136, rs1421085 and rs9930506) have been consistently reported to be associated with obesity in recent studies [7, 12, 22, 23], but there have been no studies tested the potential role in antipsychotic-related obesity except rs9939609. Here, FTO is linked to obesity due to melanocortin 4 receptor deficiency.