Researchers have found that one form of a gene involved in controlling appetite is more frequent among anorexics, a discovery that suggests disruptions of the brain's system for governing food intake contribute to eating disorders.
This is the first time an anorexia-related gene has been identified, though researchers have known for several years that a person's chances of developing an eating disorder depend partly on genetics.
The study by researchers from Germany and the Netherlands found that 11 percent of anorexics had a variant form of the gene for agouti-related protein, a chemical messenger that stimulates appetite. In contrast, only 4.5 percent of subjects without anorexia had the variant form.
The study compared 145 anorexia patients and 244 people without the disorder, and concluded that having the mutation more than doubles the chance of developing anorexia.
The finding suggests that a drug mimicking agouti-related protein might help some anorexics regain their appetites. Researchers believe that many genes work together with environmental factors to cause eating disorders.
The study was published in Molecular Psychiatry.
Anorexia affects about 1 percent of teen-age girls in the United States, and sometimes occurs in boys as well. It causes an obsession with dieting and thinness so powerful that it sometimes proves fatal.