GNB3 and obesity due to melanocortin 4 receptor deficiency: The Gβ3s variant has been associated with increased signal transduction and ion transport in the cell, and with pathophysiological conditions such as hypertension,15-19 obesity,20,21 seasonality,22 and depression.23 In addition, Dishy et al.24 reported an association between the GNB3 825C/ T polymorphism and weight gain during pregnancy.