Washington: Scientists have linked the eating disorder anorexia to variants in a gene coding for an enzyme that regulates cholesterol metabolism.
The study suggests that anorexia could be caused in part by a disruption in the normal processing of cholesterol, which may disrupt mood and eating behaviour.
For this project-the largest-ever sequencing study of anorexia - Nicholas J. Schork, a professor at The Scripps Research Institute (TSRI) worked with an international team of collaborators representing more than two dozen research institutions.
The project made use of genetic information from more than 1,200 anorexia patients and nearly 2,000 non-anorexic control subjects.
For an initial "discovery" study in 334 subjects, the researchers catalogued the variants of a large set of genes that had already been linked to feeding behaviour or had been flagged in previous anorexia studies.
Of more than 150 candidate genes, only a handful showed statistical signs of a linkage with anorexia in this group of subjects.
One of the strongest signs came from the gene EPHX2, which codes for epoxide hydrolase 2-an enzyme known to regulate cholesterol metabolism. "
The team followed up with several replication studies, each using a different cohort of anorexia patients and controls, as well as different genetic analysis methods. The scientists continued to find evidence that certain variants of EPHX2 occur more frequently in people with anorexia.
Schork noted that people with anorexia often have remarkably high cholesterol levels in their blood, despite being severely malnourished.
The study has been published online in the journal Molecular Psychiatry.