28 Yeo Yeo GS GS Connie Connie Hung CC Hung CC Rochford Rochford J J Keogh Keogh J J Gray Gray J J Sivaramakrishnan Sivaramakrishnan S S O’Rahilly O’Rahilly S S Farooqi Farooqi IS IS A de novo mutation affecting human TrkB associated with severe obesity and developmental delay A de novo mutation affecting human TrkB associated with severe obesity and developmental delay Nat Neurosci Nat Neurosci 2004 2004 7 7 1187 1187 1189 1189 15494731 15494731. This evidence concerns the gene NTRK2 and obesity due to melanocortin 4 receptor deficiency.