CPXCR1 and obesity due to melanocortin 4 receptor deficiency: Our results indicate a possible contribution of CNVs in LEPR, NEGR1, ARHGEF4, and CPXCR1 and the intergenic regions 12q15c, 15q21.1a, and 22q11.21d to the development of obesity, particularly abdominal obesity in Mexican children.