TLR3 mutation - A mutation in TLR3 has been reported in 1 of 3 patients with influenza-associated encephalopathy. TLR3 deficiency has also been reported in two patients with HSV encephalitis. TLR3 is important for innate viral defense through the induction of IFN alpha/beta.
Severe T Cell Defects
Severe T cell defects - Patients with severe T cell defects such as SCID may develop life-threatening infections when exposed to influenza virus. Patients with other severe T cell deficiencies are also at risk for severe influenza infections (ex. MHC class II deficiency, Wiskott-Aldrich, ZAP70 deficiency, complete DiGeorge, etc).