As stated above, the MD patient (deletion of the SNORD116 cluster) displays many similarities to other PWS patients, including hyperphagia and obesity in childhood.5 Mice that lack the paternal PWS critical region (PWScrp−/m+), which harbors the Snord116 cluster in the 7qC region homologous to the human 15q11-13, have been created by Skryabin et al.30 (Fig. 4a). This evidence concerns the gene SNORD116 and obesity due to melanocortin 4 receptor deficiency.