This article reviews the literature on genetic factors in anorexia nervosa. Twin studies in which monozygotic and dizygotic twins are compared concerning the concordance of anorexia nervosa, show certain methodological shortcomings.

Nevertheless anorexia nervosa seems to be more frequent among monozygotic twins. In addition to a possible genetic predisposition for anorexia nervosa, the difference in concordance between monozygotic and dizygotic twins can be explained by other theories.