Author(s)

Kewen Qu, Xiran Tang and Shuyue Yang

Corresponding Author

Kewen Qu

ABSTRACT

Behavioral genetic methods have been largely used in research to study the genetic and environmental risk factors of human mental disorders, including the eating disorders (EDs). Among these quantitative methods, twin and adoption study designs are powerful tools in identifying the nature and nurture components leading to EDs. Molecular genetic methods are introduced in studying EDs recently to study specific candidate genes on human genome. The present work is to (a) review twin and adaption studies of the eating disorders; (b) summarize the major findings in the context of heritability, environmentality, and their interplay under the ACE model; (c) explore the candidate genes for understanding the fundamental cause of EDs on a molecular base. On the basis of this review, the contribution of heritability lies in the range of 0.41 to 0.65. Shared environmental influences are considered neglectable and non-shared environmental influences occupy 0.35 to 0.64. Anorexia Nervosa (AN) and Bulimia Nervosa (BN) vary in these categories but only to a limited extent. Different sexualities and specific experiences of individuals might interact with the genetic risk of EDs. Several candidate genes are identified at the molecular level, but more are yet to be discovered in future studies. Based on the reviewed twin studies and adoption studies, we conclude that heritability contributes to a large extent to general EDs while the rest is accounted by non-shared environmentality. Other specific factors, including subcategories AN and BN, sexualities, specific symptoms, exhibit different variabilities on the heritable and environmental risks of EDs.

KEYWORDS

Eating disorders, twin study, adoption study, quantitative genetics, heritability, environmentality