I need to ask....other than posting, have you spent time reading sticky's and threads on these forums? Please read read read....though your questions are fully appreciated, a good way to learn and are great questions...reading up on things will help too.
Yes, SA can be hereditary. It is not about just the symptoms (which some do and do not have), but the body structure and so on.
I'm only a sufferer, not a medical pro. What I post are my thoughts as a sufferer, not that of the ASAA. As a moderator on these forums I oversee the posting rules. This is the internet, always discuss what you read with your medical team.