Eye color may be genetically linked to alcoholism, reports a new study by genetic researchers at the University of Vermont. The results suggest hopes of finding the roots of alcoholism, and potentially many other psychiatric illnesses.
Study leaders Arvis Sulovari, and Dawei Li, Ph.D., found that mostly European Americans with light-colored eyes, including green, grey and brown in the center, had a higher incidence of alcohol dependency than those with dark brown eyes.
The strongest tendency towards alcoholism was among blue-eyed individuals. The study details the genetic components that determine eye color, demonstrating that they line up along the same chromosome as the genes related to excessive alcohol use.
“This suggests an intriguing possibility – that eye color can be useful in the clinic for alcohol dependence diagnosis.”
But, Li says, scientists still don’t know the reason, and further research is needed.
Working with physicians and scientists throughout the Northeast, Li collaborated in building a clinical and genetic database of more than 10,000 people, primarily African Americans and European Americans, diagnosed with at least one psychiatric illness. Many have multiple diagnoses of diseases, including depression, schizophrenia and bipolar disorder, as well as addiction and alcohol or drug dependence.
From their large database, Li’s and Sulovari’s study searched for the alcohol-dependent patients with European ancestry, a total of 1,263 samples. When Sulovari discovered the eye-color connection, they retested their analysis three times, arranging and rearranging the groups to compare age, gender and different ethnic or geographic backgrounds, such as southern and northern parts of the continent.
“What has fascinated me the most about this work has been investigating the interface between statistics, informatics and biology,” says Sulovari. “It’s an incredible opportunity to study genomics in the context of complex human diseases.”
Eye color: A potential indicator of alcohol dependence risk in European Americans
Arvis Sulovari, Henry R. Kranzler, Lindsay A. Farrer, Joel Gelernter and Dawei Li
American Journal of Medical Genetics: Neuropsychiatric Genetics (Part B) | DOI: 10.1002/ajmg.b.32316