The positive correlation between overweight and MT-CO2 expression and between obesity and MT-ND1 and MT-ATP6 expression that we determined in the SIP cohort placentas can therefore be attributable to the attempt by mitochondria to respond to the MPSP effect while also battling the effect brought about by obesity. The gene discussed is MT-ATP6; the disease is obesity due to melanocortin 4 receptor deficiency.