No. Encephalitis is an inflammatory process involving the brain that is usually caused by infection, either viral or bacterial.
No but maybe. Congenital brain infections are caused by "genetic" acquired infection from the mother. Otherwise brain infection is acquired without genetic cause.
No, autoimmune. Nmda receptor encephalitis is an autoimmune disorder in which the immune system gets sensitized to an antigen which closely matches the normal nmda receptors and then attacks the brain cells which have those receptors. Often this is triggered by a cancer, a so-called "paraneoplastic syndrome"; this is not a genetic disorder. Read more...