SPTLC3 and obesity due to melanocortin 4 receptor deficiency: In the obesity study, strong genetic control of body fat set-point as well as microbiome plasticity was unraveled, and multiple genetic loci were identified for obesity traits and dietary responses (e.g., Sptlc3, Klf14, Degs1, Npc, Cbr1, and amylases) (Parks et al. 2013).