Eating disorder predisposition toward eating disorders as a result of Mendelian inheritance. Twin studies have found a slight instances of genetic variance when considering the different criterion of both anorexia nervosa and bulimia nervosa as endophenotypes contributing to the disorders as a whole. A genetic link has been found on chromosome 1 in multiple family members of an individual with anorexia nervosa. An individual who is a first degree relative of someone who has had or currently has an eating disorder is seven to twelve times more likely to have an eating disorder themselves. Twin studies also show that at least a
Other specified feeding or eating disorder in the literature, as it was perceived to be uncommon compared to the other defined eating disorders. In "DSM-III-R", published in 1987, the Atypical Eating Disorder category became known as Eating Disorder Not Otherwise Specified (EDNOS). "DSM-III-R" included examples of individuals who would meet criteria for EDNOS, in part to acknowledge the increasingly recognized heterogeneity of individuals within the diagnostic category. In 1994, "DSM-IV" was published and expanded EDNOS to include six clinical presentations. These presentations included individuals who: A disadvantage of "DSM-IV"'s broad EDNOS category was that people with very different symptoms were still classified as having the same