Why wouldn't you get citizenship? I'm in Australia too, and a citizen now as well (born in England). I don't recall ever being asked if I had any condition like Asperger's Syndrome or autism; it just never arose, although I have to confess I was very young at the time, it was back in the 1970's, and it's possible they may have asked my parents if any of us had anything that would have disqualified us from becoming citizens.
It seems that your family for whatever reason, escaped scrutiny of Australia's Migration Act when immigrating. But then you wouldn't be asked about having Aspergers Syndrome in the 1970s either.
http://www.news.com.au/lifestyle/re...a/news-story/02b91be7758e5090c03e50910a7391c6