ZFYVE9 and obesity due to melanocortin 4 receptor deficiency: Exploring the individual genes, several of them were related to morbidity in TS e.g. aortic aneurysm (ZFYVE9), obesity (CNR1), melanocytic nevi (DOCK7)49, and the insulin-like-growth factor system (IGFBP3), which is known to be perturbed in TS50.