We next examined CNVs >1 Mb and found several genes that are a priori candidates for obesity. Two of the strongest candidates are UCP1 and IL15, which are located within the same 2.1-Mb deletion on chromosome 4q31 (Fig. 1). The case carrying this CNV has moderate obesity (BMI 46.2 kg/m2). Numerous studies relate UCP1 to obesity in animal models (17), and associations have been reported in humans (18). We validated this CNV by a CNV-typing platform, the Affymetrix Cytogenetic arrays (supplementary Fig. 4). Since parental DNA is also available, we assessed both parents and found that the CNV is inherited from the father. Another large CNV on chromosome 4q22.1 contains two potential candidate genes (NAP1L5 and SNCA), and it is present in a subject with moderate obesity (BMI 49.0 kg/m2) (Fig. 2). NAP1L5 is an imprinted gene, which is of interest because of associations of body weight and obesity with genomic imprinting (19). Differences in paternal and maternal copies of this gene have been related to body weight at birth and in adulthood in mice (20). We validated this CNV
