I don’t know if the Church has made any official statements on this probably because it hasn’t been studied enough. I don’t think there is a clear consensus among scientists how to define it. Additionally, as others said, because it is so rare and resources are limited, the Church might not see a great enough need yet to discuss it in detail. Whether a person should be male or female would depend on the specific case. I can’t see gender transitioning being allowed even for intersex people, except at birth where the parents would have to decide which gender to raise their child as. For example, if a person had reproductive organs for both male and female, I don’t think that would give them permission when they turned 18 to, for example, transition from male to female. The Church would expect them to remain with the gender their parents raised them. This would be assuming they were truly intersex. If the parents wrongly raised a girl as a boy, she would definitely be allowed to show her true identity once she found out the truth. I would consider that child abuse by the parents too.