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. This evidence concerns the gene GNB1 and obesity due to melanocortin 4 receptor deficiency.