Indeed, you're right. About 1% of the population exhibits no sexual attraction whatsoever [http://en.wikipedia.org/wiki/Asexuality], though I wouldn't be able to say how often this is intrinsic. Asexuality (or hyposexuality) are both symptoms that sometimes emerge from child sexual abuse, and victims of violent sex crime, much of which has only in the modern era begun to be regularly reported. In fact, I'm surprised at the 1% statistic.
Things get complicated once one introduces all the genderqueer possibilities, but this is not to say they are to be disregarded. Part of the complexity comes from the delineation between gender (psycho-social sexual identity) and sex (the physiological sexual identity), both of which can be aligned, counteraligned, misaligned, third-polar, bi-faceted, polyfaceted, neutral, fluid and so on. And this is independent of sexual orientation. And then there are sexual orientations towards all of these. The debate continues as to whether they are merely fetishes or minutial paraphilic categories, or require consideration all their own. It's like ordering a customized coffee-based beverage from Starbucks.
238U.
