Scientists have linked a gene active mainly in fat and muscle, not the brain, to an increased risk of anorexia nervosa, in a finding that challenges how the eating disorder is understood.

The Michigan State University-supported study, published in Frontiers in Psychiatry, sequenced protein-coding DNA from 154 patients. Those with anorexia were nearly four times as likely as a reference population to carry rare, potentially damaging variants of the PLIN4 gene.

About 11 percent of patients carried such variants, compared with 3.2 percent in the reference group, an odds ratio of 3.86 that survived stringent statistical correction.

PLIN4 regulates how cells store fat. The finding raises the possibility that altered fat metabolism contributes to anorexia in some patients, shifting focus from purely brain-based explanations.

Study adviser A.J. Robison said the result ‘flies in the face of the dogma’ that anorexia genes act in the brain. Collaborator Michael Lutter, who treats eating-disorder patients, helped design the work.

The authors stress this is a clue, not a test. But it opens new avenues for research and, eventually, treatment.