As far as I know you can not pass AA to someone else unless you are their children and it is hereditary - as in the chromosome defect, otherwise AA is environmental and 50% of the AA cases are idiopathic ( or unknown). I was diagnosed a year ago as an idiopathic and I am doing great. I am 28 years old and live a normal life although my blood counts not at normal levels, but close enough. I am sure you know this website, but here it is anyway. www.aplastic.org Hope that helps.