Hairless cats are not hypoallergenic because it is very often not the hair that a person is allergic to. What most people are allergic to is a protein in the cat's saliva called Fel D1. So when the cat grooms itself, which all cats do, hairless or not, its saliva will dry, turn into microscopic dander, and there you have allergies! It is said that altered (spayed or neutered) animals have less of this protein in their saliva and that females generally have lower amounts of it. Your best bet would be to get a fixed female cat. But it would still cause an allergic reaction in very sensitive people.
If the person with allergies lives in the same house, keep the cat out of that person's bedroom and out of their closet/clothes storage area. Get a HEPA air filter. When you dust, vacuum, or do any dander-raising cleaning, do it while the allergic person is not home, and allow as much time as possible for whatever is stirred up to re-settle. Have the allergic person take a 24-hour allergy pill, if possible.
If you are worried about allergic visitors, suggest they take allergy medication just prior to coming or meet them other places than your home (this is what I do).
I hope it works out for you!