W. Va. Code § 61-8B-12: Same -- Defense.

(a) In any prosecution under this article in which the victim's lack of consent is based solely on the incapacity to consent because such victim was below a critical age, mentally defective, mentally incapacitated or physically helpless, it is an affirmative defense that the defendant at the time he or she engaged in the conduct constituting the offense did not know of the facts or conditions responsible for such incapacity to consent, unless the defendant is reckless in failing to know such facts or conditions.

(b) The affirmative defense provided in subsection (a) of this section shall not be available in any prosecution under subdivision (2), subsection (a), section three, and under subdivision (3), subsection (a), section seven of this article.