Many individuals who suffer from an eating disorder, such as anorexia nervosa, seem to suffer a lifetime sentence with the illness. They remain severely underweight and are at risk of dying from malnutrition.
Although no treatment has been found, a new study by scientists at the University of California, San Diego (UCSD) School of Medicine and the Scripps Translational Science Institute (STSI) in La Jolla, CA, reveals that genetic variations may be a factor in whether or not the disorder becomes a chronic issue.
It has been theorized that individuals may be genetically predetermined to carry personality traits and temperaments that make them more prone to eating disorders. The new study could help pave the way toward more individualized therapy for these patients.
“This study sheds light on important ‘SNPs’ or genetic variations within an individual’s DNA, associated with long-term, chronic eating disorders,” said Dr. Walter H. Kaye, professor of psychiatry and director of UCSD’s Eating Disorder Treatment and Research Program, who was senior author with Nicholas J. Schork, director of bioinformatics and biostatistics at STSI and professor at The Scripps Research Institute.
“These variations suggest genetic predictors for patients who may be particularly susceptible to eating disorders and whose illnesses are most difficult to treat effectively,” said Kaye.
Kaye noted that these genetic traits are also linked to individuals with higher anxiety and more concern over making mistakes — characteristics associated with bulimia and anorexia.
“Anorexia and bulimia likely stem from many different causes, such as culture, family, life changes and personality traits,” said Cinnamon Bloss, an assistant professor at STSI,
“But we know biology and genetics are highly relevant in terms of cause and can also play a role in how people respond to treatment. Understanding the genetics behind these conditions is important, because it could eventually help us tailor treatment based on the person’s genetic makeup, with the goal of more personalized and effective treatments.”
A total of 1,878 women were analyzed in the large-scale candidate gene association study, which was designed on hypotheses regarding the genes, pathways and biological systems linked to eating disorder susceptibility. Most of the women had a lifetime diagnosis of either anorexia or both anorexia and bulimia, and also had a lower body mass index, higher anxiety and higher worry over making mistakes than control subjects.
The team was able to pinpoint the top 25 most statistically significant SNPs (single-nucleotide polymorphisms), after evaluating a total of 5,151 SNPs in approximately 350 genes. According to Bloss, 10 of the 25 most strongly associated haplotypes involved SNPs in GABA genes.
The strongest link to chronic symptoms involved an intronic SNP on chromosome 4 of the gene GABRGI. “The study suggests genes that may pre-dispose individuals to a chronic course of an eating disorder,” Bloss said, adding that further studies are needed to confirm these associations.
“Individuals with anorexia in particular are often resistant to treatment and lack awareness of the medical consequences of their behavior, which can result in chronic, protracted illness and even death,” said Kaye.
“The question for us became, ‘Are there prognostic factors that might help clinicians identify good versus poor outcomes for treatments including medication or psychotherapies?’”
The findings are reported online in the journal Neuropsychopharmcology.
Source: University of California