FTO and obesity due to melanocortin 4 receptor deficiency: The proximity of the retinitis pigmentosa GTPase regulator interacting protein-1like (RPGRIP1L) gene transcription site and the the 5’ end of FTO [20], may affect RPGRIP1L expression in the brain via FTO genetic polymorphisms, leading to obesity development by influencing leptin signalling [21], and increasing its secretion [6].