A discovery set of 300 UK Caucasian patients from the Genetics of Obesity Study (GOOS) cohort were randomly selected for this study (143 had developmental delay). All patients had severe obesity defined as a BMI standard deviation score (s.d.s.) >3 and onset of obesity before 10 years of age (Supplementary Information). Mutations in LEPR, POMC and MC4R were excluded by direct nucleotide sequencing and a karyotype performed. DNA samples were run on Affymetrix Genome-Wide Human SNP Array 6.0 by Aros, Inc., and compared to control data on the same platform obtained on over 7,000 controls recruited from the Wellcome Trust Case Control Consortium 2 (WTCCC2) and the Genetic Association Information Network (GAIN). The WTCC2 data set contains 6,000 individuals, 3,000 from the 1958 British Birth Cohort and 3,000 from the UK Blood Service Collection, used as common controls in genome-wide association studies of 13 disease conditions undertaken by Wellcome Trust Case Control Consortium 2 (http://www.wtccc.org.uk/ccc2). The GAIN data set contains 1,442 individuals of European ancestry used as part of the control cohorts in genome-wide association studies of schizophrenia and bipolar
