Short-list of eating-disorder phenotypes identified

Researchers have identified a short-list of eating-disorder phenotypes, which may hold the key to understanding vulnerability to anorexia nervosa and bulimia nervosa.A combination of both genetic predisposition and environmental factors affect a person's likelihood of developing anorexia nervosa and bulimia nervosa. However, this combination makes identifying relationships between phenotypes and genotypes challenging. There exists a need for novel, systematic approaches to selecting and evaluating the appropriateness of traits from a large pool. Bulik et al. conducted a structured analysis of the phenotypes of individuals with eating disorders in order to develop an approach to the efficient selection of variables, and the teaming of variables with linkage methods, for further application in genetic research.Over 100 psychiatric, personality and temperament phenotypes of individuals with eating disorders from 154 multiplex families with an anorexia nervosa cohort and 224 multiplex families from a bulimia nervosa cohort were measured. Three heritable quantitative traits - obsessionality, age at menarche, and a composite anxiety measure - all showed normal distribution and familial correlation making them ideal for quantitative trait locus linkage analysis. Variables showing minimal familial correlations, yet demonstrating strong familiarity when considered in their ability to cluster families were considered appropriate for covariate linkage analysis. The three deemed most suitable included minimum body mass index, concern over mistakes and food obsessions. Thus the authors developed an algorithm for utilising a large set of phenotypes collected from two multiplex samples of eating disorder families, to select a set of variables, and the linkage methods paired to those phenotypes, that would be useful for further genetic analysis. Reference...