thanks a lot!

來源: 於 2009-03-18 05:10:25 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

Down syndrome (trisomy 21) is the most commonly recognized....

That means down is trisomy. my probability is only 1/3500. great. no need for invasive test. haha.