GAD2 and obesity due to melanocortin 4 receptor deficiency: In order to evaluate the potential relationship between other common SNPs in GAD2 and severe obesity, we conducted a comprehensive investigation of haplotype structure in this region using the data from the International HapMap Project (http://www.hapmap.org/cgi-perl/gbrowse/gbrowse/hapmap) and Haploview (http://www.broad.mit.edu/mpg/haploview/index.php) [25].