Both MEG3 and FTO exhibit a sex-dependent expression pattern in children without obesity, while in children with obesity, this sex-related variation is also observed for SREBP1, FASN, ACACA, FTO, and MEG3, suggesting a potential role of sex in the regulation of lipogenic genes under obesogenic conditions. The gene discussed is SREBF1; the disease is obesity due to melanocortin 4 receptor deficiency.