Mez said that the results, albeit early, are a step towards a better understanding of the disease. "It helps us to better understand biologically and mechanistically what is going on in the brain in the CTE.
"In understanding the mechanism and identifying this genetic risk factor, we have new potential targets for the development of therapies," he said.
The authors point out that their findings must be further investigated and replicated in a larger group in order to draw definitive conclusions.
Continue with caution
Gandy, who was not involved in the study, wrote in an e-mail that the results were "not ready for primetime."
"We need to be careful, the study shows that the gene may be associated with a lower risk of CTE, but the CTE is a polymorphic, polyphenotypic and polygenic disease. [and] Focusing on a gene that can reduce risk can be stretching, "wrote Omalu, who also was not involved in the new research, in an e-mail.
Mez and his Boston University team are also studying other genes that might play a role in the CTE. "If these other genes have an effect, it is probably independent and additive to the TMEM finding."
Mez added that it is "likely that multiple genes throughout the genome contribute to CTE risk and severity, and if we look at them all together, it will improve our predictive ability."
Today, the CTE can only be diagnosed after death. It is believed to result from repeated head trauma. In football, this can happen not only through hard blows to the head, which lead to a concussion, but through the repeated rattling of the brain in the skull while tackles and falls on the lawn. These repeated hits are called subconcussive hits and can lead to a kind of protein called tau in the brain.
Early and prolonged exposure to repeated trauma is also considered a likely pathogen. There is no treatment or cure for the disease.
Gene variant bound to less severe CTE
The researchers found no connection between the gene variant itself and the CTE. Those with CTE and the gene variant had lower levels of tau and less brain inflammation than those with CTE, but no variant.
Both inflammation and buildup of tau in the brain contribute to degeneration of the brain.
"For people with CTE, these CTE-related outcomes were more severe, they were more likely to have dementia, and they had more of a progressive neurodegeneration in their brain," Mez said.
In a study from last year, researchers from Boston University have described in detail the determination of the CTE in the brain of 100 out of 101 former NFL players. And although the presence of the disease in the study is extremely high, it is difficult to extrapolate to the general prevalence among football players and the general public, as the brains studied had a potential bias: they were donated by relatives because the subjects This probably had symptoms of the disease such as memory loss, confusion, depression and impulse control problems.
Understand the difference
"Although this research shows early that there are some genetic risk factors, there was no difference between those with and without CTE." The TMEM106B gene was also associated with frontotemporal dementia, suggesting a possible overlap with a range of neurodegenerative diseases. Manley, who was not involved in the study, wrote in an e-mail. "With a large number of individuals with and without long-term problems, more research is needed to fully understand their cause and effect."
Mez noted, "We see many former athletes who have a similar level of exposure, two football players who have played for eight to ten years, later in life one of them becomes seriously ill and the other may be slightly affected.
"I think it's valuable to understand that difference, and that insight explains these differences," he said.