INSIG2 and obesity due to melanocortin 4 receptor deficiency: Other GWA studies have reported variants in the proximity of INSIG2 [15,16] and within PFKP [2,16] as novel obesity gene loci, however, attempts to replicate the association for the INSIG2 variant have been inconsistent [17-24], which also appears true for variation in PFKP [17].