GNB1 and Obesity: While we do not know if obesity was present in the patients reported in Lohmann et al with LoF variants, this phenotype may represent a hallmark of the spectrum associated with haploinsufficiency in GNB1. The milder phenotype observed in these cases may be due to a wide spectrum of expressivity associated with damaging variants in GNB1. For instance, Petrovski et al. reported a patient with a p.Gly77Ser missense variant who was severely affected with severe global developmental delay, brain abnormalities, and epilepsy without the ability to ambulate independently.