LEP and obesity due to melanocortin 4 receptor deficiency: Moreover, of the 57 mutations identified in the LEP gene reported in humans, both homozygous and heterozygous, 1.5% are likely benign, 18% are benign, 1.5% are likely pathogenic, 21% are pathogenic, and 58% are unknown [67]; thus, the genotypic profile of LEP is of interest in obesity.