Lets say a woman and man are diagnosed with the same exact disorder:
It can be anything (narcissism, OCD, bipolar, psychopathy, Asperger syndrome, borderline, etc). I would assume there are still differences in the gender. For instance a female suffering from any of that wouldn't display signs that are typical of her male counterpart and vice-versa. Maybe there are just as many female narcissists too but they won't display the same traits as male narcissists.
Would you say the traits of the same disorder differ between the genders?