Reprinted from Eating Disorders Review
September/October 2001 Volume 12, Number 5
©2001 Gürze Books
Q: I’ve seen several families in which one girl has anorexia nervosa but her sister or sisters don’t. Since these girls are raised in the same family, I wonder what accounts for the fact that they don’t all develop eating disorders. (Betty K., Miami)
A: The fact is, sisters of girls with anorexia nervosa are at increased risk of developing this disorder themselves, because it does run in families. Fortunately, only a few sisters of girls with anorexia nervosa also develop it. What differentiates these sisters is still a matter of debate and research. A recent study of 45 sister-pairs suggests that those developing anorexia nervosa differed from their healthy sisters in several ways: They were more likely to be perfectionistic and/or compliant, have feeding difficulties in childhood, be subject to higher parental expectations, report sexual abuse, be highly competitive with their sisters, perceive their sisters to be their parents’ favorite, and perceive their sister’s appearance and shape to be superior to their own. Thus, intrinsic temperamental traits, parental pressure and external events such as sexual abuse all appear to be important. In this group, no differences were found between sisters who were healthy and those with anorexia nervosa with respect to the percentages having various alleles for several suspected genetic markers involving two different serotonin receptors, the DRD4 dopamine receptor or catecholomethyltransferase (Psychological Medicine 2001; 31:317).