"Gender is a social construct" refers to things like, inherent intelligence differences, or inherent behavioural differences, like women being more suited for the kitchen and men for the workplace, skirts versus pants, etc. This can be demonstrated by pretty simple common sense-for example, only women wearing skirts isn't a universal rule. Look at kilts, for example.
The "gender is innate" thing more has to do with the body-that men inherently prefer having penises, and will be upset if it is lost, and women inherently prefer having vaginas/breasts, and will be upset if those are missing. Not to mention, the hormonal differences: men with testosterone levels that are too low are made uncomfortable by it, while women, born with naturally lower testosterone levels, don't mind, and instead are made uncomfortable by having testosterone levels too high.
The two statements both use the word "gender", which can be confusing, because they are actually talking about two completely unrelated concepts.
Also, between people here who hate feminism on principle, and who hate transsexuals on principle, you've basically come to one of the worst places to get good information on the subject.
