In addition, several common and rare copy number variants (CNV) contributing to the heritability of BMI and obesity have been reported, including deletions upstream of the NEGR1 gene [13], proximal and distal deletions at 16p11.2 [20], gains at 10q26.6 containing the CYP2E1 gene (MIM 124040) [21], and homozygous deletions at 11q11 encompassing olfactory receptor genes [22], among others. This evidence concerns the gene NEGR1 and obesity due to melanocortin 4 receptor deficiency.