My husband claims to have dyscalculia. No one ever told him he had it. I think in his case math was just always his weakness, but I have my doubts it is beyond that. I do believe in the condition, though.
When my husband must do math, he struggles, but can usually manage the basic stuff. He certainly has his other strengths (languages). I can't help but wonder if his ADD plays some role in his math difficulties. His ADD is a definite and formally diagnosed health issue. The relationship seems feasible. He was only diagnosed with ADD in his early 50s, but the condition was surely present when he was a young student. His time management skills are quite lacking and he can't multi-task. He gets so easily distracted.