CREBRF and obesity due to melanocortin 4 receptor deficiency: In a similar spirit, Southam et al. examined all known type 2 diabetes and obesity-associated variants at the time (n = 30 loci in 2009), but did not find a similar pattern [44]; this is surprising in light of the findings of Byars et al., case studies like CREBRF, as well as other work on human complex traits more generally [45, 46].