B4GALT1 and obesity due to melanocortin 4 receptor deficiency: Examples of other protective variants include the N352S variant in B4GALT1 which is protective against cardiovascular disease (Montasser et al. 2021) and protein-truncating variants in GPR75 which reduce the risk of obesity (Akbari et al. 2021), as well as the A88V variant in Gjb6, which protects against hearing loss in mice (Kelly et al. 2019).