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
Eating Disorder Inventory EDI as well as EDI-2, it has been enhanced to reflect more modern theories related to the diagnosis of eating disorders. It was designed for use with females ages 13–53 years. It contains 91 items divided into twelve subscales rated on a 0-4 point scoring system. 3 items are specific to eating disorders and 9 are general psychological scales that while not specific are relevant to eating disorders. It yields six composites: Eating Disorder Risk, Ineffectiveness, Interpersonal Problems, Affective Problems, Overcontrol, General Psychological Maladjustment. It is also a self-report questionnaire administered in twenty minutes. The Eating disorder symptom checklist (EDI-3SC)