No. They are born. We no longer say abnormal. Just different. As for the moral teachings of the Church, they should unravel if they are based on the views of asexuals living out their natural sexual identity and assuming it to be universal. The only way to undo the damage of Humanae Vitae is for them to out themselves and the rest of us to start from scratch. Chastity is not a marital virtue once you exclude cheating. Respecting a spouse’s refusal of sex, including sodomy is appropriate, as is consensual sodomy.

http://www.whatisasexuality.com/intro/