A new study presented this week at the Association of Academic Physiatrists Annual Meeting in Atlanta found that a genetic risk score could help predict a patient's quality of life after a traumatic brain injury. One day, physicians could have a simple, early method to forecast a patient's recovery and personalize therapy to maximize their quality of life down the road.
"Gene pathways can influence all of our biological functions and risk for many health outcomes," says Mark Linsenmeyer, MD, a resident physician at the University of Pittsburgh Medical Center and the primary author on the study. "Each person has a unique inherited genetic code. By studying one gene pathway in a large group of people with the same disease or health problem, we hope to unlock clues to why some people have different outcomes than others. This knowledge may be used to help physicians make the best treatment choice for each person."
Dr. Linsenmeyer, as part of Dr. Amy Wagner's Rehabilomics research team, recently set out to investigate how genes that affect the brain's dopamine pathways could predict recovery in people with moderate-to-severe traumatic brain injury. The team recruited 94 adults with traumatic brain injury from a level-1 trauma center. They honed in on five particular genes in the dopamine pathways: COMT rs4680, VMAT2 rs363226, DRD2 rs6279, ANKK1 Taq1a, and MAOA VNTR. They defined which "risk genotypes" were associated with lower average scores on surveys filled out by traumatic brain injury patients to describe their overall quality of life both six and 12 months after their injuries.
The researchers analyzed how individual variants of each of these five genes could affect patients' quality of life, and then generated a weighted gene risk score as a measure to reflect cumulative risk represented by all genotypes included in the score. Based on available literature about dopamine pathway genetics, they predicted that their gene risk score calculation tool should be specific to a patient's sex.
Before they calculated gene risk scores, the research team noticed that only one gene, COMT, could significantly predict quality of life for a subset of patients six months after their injuries. After generating sex-specific gene risk scores, they found that variants of all five genes on the dopamine pathway could meaningfully contribute to a gene risk score that was highly predictive of quality of life after six months for TBI patients of both sexes, and also predictive of quality of life after one year for women.
"Gene risk scores based on dopamine pathway genes and other factors could one day be a useful tool for physicians treating people with traumatic brain injury," explains Dr. Linsenmeyer of the study's findings. "This score could be used early in a patient's post-injury recovery to predict potential outcomes and prescribe more individualized therapy, a practice also known as precision medicine."
Next steps for the Rehabilomics research to inform precision medicine efforts in this area include further validation of this study's findings and identification of other genetic factors that may influence recovery from traumatic brain injury.