A team of international researchers has discovered a genetic variation that can help explain why some people become very ill from the flu virus, while others only suffer minor symptoms.
The gene involved is from the interferon-inducible transmembrane protein family, and is called IFITM3. People with a variation of the IFITM3 gene are more likely to become extremely ill when plagued by the flu. According to Abraham Brass, MD, PHD, of Massachusetts General Hospital, in Boston, IFITM3 enhances the body’s ability to fight off certain strains of the flu virus.
Dr. Abraham Brass and his team of researchers first discovered the antiviral role of IFITM3 in genetic screening tests that showed that the gene helped impede the growth of the flu virus, dengue virus, and the West Nile virus in cells. However, researchers were still unclear as to the role of IFITM3 in living animals and humans. Therefore, Paul Kellam, PHD, of the Sanger Institute in Cambridge, UK, and Brass, went on to study the effects of the influenza virus on mice that lacked the gene. Kellam and Brass found that once these mice were introduced to the influenza virus, they suffered severe symptoms associated with the flu. Specifically, in the mice lacking the gene, the influenza virus replicated more times and led to severe pneumonia.
Most importantly, after sequencing the genes of 53 patients who were admitted to the hospital for inpatient care due to the pandemic or seasonal flu, researchers found that a larger portion carried a variant of IFITM3 compared to the general population. Researchers believe that this variant results in a shorter version of the protein, which leaves patients more susceptible to the flu.
This genetic discovery holds great implications for medicine in the future. New medicines and vaccines can be more easily created to target viruses such as H1N1 and the bird flu. In addition, with genetic screening available, patients who carry the variant of the gene can now be treated with preventative vaccines. Furthermore, with the discovery of the gene, researchers and professionals in the medical arena will have an advantage in the monitoring and controlling of future flu pandemics.
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