I'm assuming that some day in the future it may develop into something a bit more serious but at the moment I'm perfectly fine (if a little chilly..). I wouldn't stress about it now. Obviously keep an eye out for any possibly symptoms etc and see your doctor if anything unusual is happening but I really wouldn't worry about it now.
It could just be that you have inherited a predisposition to the disorder, but that it may never fully develop as it has with your family. As your mum is only borderline this could easily be the case.