Tick-Borne Encephalitis: Gene Risk Factor Discovered by Researchers

Researchers at the Medical University of Graz have identified a genetic factor linked to susceptibility to tick-borne encephalitis (TME), also known as Frühsommer-Meningoenzephalitis (FSME). The discovery, stemming from an international study analyzing the genomes of approximately 1,600 individuals, could pave the way for new treatment strategies for the disease.

The study, led by Werner Zenz of the Med Uni Graz’s Clinical Department for General Pediatrics, focused on identifying genetic variations that correlate with FSME infection. Researchers analyzed around 700,000 genetic variants per person, comparing data from patients in Austria, Slovenia, Czech Republic, Poland, Estonia, Latvia, Lithuania, Germany, England, and Austria against healthy control groups. The findings, published earlier this month, pinpoint a variant within the ABCG1 gene as a potential risk factor.

The ABCG1 gene plays a crucial role in cholesterol metabolism, facilitating the transport of cholesterol from inside cells to their surface. Laboratory experiments conducted by the Graz team revealed that blocking the ABCG1 gene hindered the virus’s ability to replicate. “Our results strongly suggest that ABCG1 is a central point of attack for the FSME virus within the human body. We have opened a new door,” said Zenz.

FSME, transmitted through tick bites, causes severe inflammation of the nervous system. Austria registers between 100 and 200 cases annually, with a significant proportion of patients experiencing long-term aftereffects. Approximately half of adults hospitalized with FSME due to meningitis and encephalitis do not fully recover upon discharge, and around ten percent suffer paralysis of a limb during their hospital stay. The mortality rate is approximately one percent.

Currently, there is no specific antiviral treatment for FSME. The research highlights the growing understanding within the medical community that an individual’s genetic predisposition plays a significant role in susceptibility to infectious diseases, alongside exposure to the pathogen itself. Piyush Gampawar and Manfred Sagmeister, the study’s first authors, emphasized the importance of this genetic link in understanding the disease’s progression.

Despite high vaccination rates in Austria, FSME cases continue to occur each year. The identification of the ABCG1 gene variant offers a potential target for future therapeutic interventions, though further research is needed to fully understand the mechanisms involved and develop effective treatments. The research team is continuing to investigate the implications of this discovery for FSME prevention and management.