Praise be to Allah.
Refer to a sharee’ah judge (qaadi) if there is any qaadi there. If not, then if the man has consummated the marriage with the woman, the mahr must be given to her because of having had intercourse with her. As for this sickness, if it prevented him from consummating the marriage or put him off from doing that properly, then whatever was paid to the one who tricked him into this marriage should give it back, if he was tricked. If that is not the case, then he does not deserve anything because he did not ask enough questions and find out information properly.