Rare MTNR1B variants impairing melatonin receptor 1B function contribute to type 2 diabetes

Philippe Froguel, Ralf Jockers and colleagues report the functional characterization of 40 rare protein-coding variants of the MTNR1B gene (encoding melatonin receptor 1B, also known as MT2). They find that functionally impaired MT2 melatonin receptors confer higher risk to type 2 diabetes in Europeans.