"Rejecting or trivializing the Genesis account about Adam and Eve creates a domino effect that undermines nearly every major teaching in the Bible! Such a way of thinking leads to a host of unanswered questions and a faith with nothing to stand on."
footnote: " These include teachings about God’s sovereignty, human integrity, good and evil, free will, the condition of the dead, marriage, the promised Messiah, a paradise earth, God’s Kingdom, and many others."
http://www.watchtower.org/e/20090901a/article_01.htm
I can attest to this being exactly the case. This combined with the global flood story made everything come crashing down like a house of cards for me. It's rather interesting that the WT on their own website makes it clear just how easy it is to go from belief to non-belief by simply questioning this one thing. It also proves that unless you actually do some reading and research on your own, you'll stay stuck in this hamster wheel of circular reasoning - which is the case with the vast majority of JW's. I actually pity them...