TNF and Lipoatrophy: In 96 white patients in England, a TNF–α position 238 polymorphism was present only in subjects with lipodystrophy (P p .0)).[43, 44] These findings support a role for TNF-α in the pathogenesis of lipoatrophy, this variant allele may simply be a marker for other genes with which it is linked, such as members of the major histocompatibility complex.[42]