New research has revealed a possible genetic cause for unusually severe cases of influenza (flu).
Writing in the journal Nature, scientists report that a variant ofthe IFITM3 gene was more common in people hospitalised for flu than in the general population. The variant is present in around one in every 400 people in general, but analysis of 53 patients hospitalised with severe flu revealed a much higher rate of one in twenty.
Researchers also found that mice without the equivalent of the IFITM3 gene developed much more serious symptoms when infected with flu than normal mice. They suggest that people with the IFITM3 variant should join other higher-risk groups in receiving annual flu vaccinations to prevent infection.
Comment: The genetics of host susceptibility both to infection and to more serious forms of disease is an important area for public health, since not only can it reveal insights about disease, but also identify the most vulnerable members of population. However, the variant reported here accounts for only some apparently unexplained (i.e. without the presence of other health problems such as respiratory disease) cases of flu complications.