TMEM18 and obesity due to melanocortin 4 receptor deficiency: Overall, we found CNVs that further implicate genes previously associated with obesity such as PTBP2, TMEM18, MYT1L, POU3F2, SIM1, SH2B1 and GNB3, and also identified other potentially relevant candidate genes including TAS1R3, ALOX5AP, and GAS6. Our study highlights the significant value of chromosomal microarrays in providing not only a genetic diagnosis for syndromic causes of obesity but in uncovering genes relevant to human obesity.