???,??

? ??????????
????????????????80-100?
?????????
???????^????
???????????????????
?????????????????????
????????????????
???????????????? ???
???,???????????????????????
????????????????????????????
????????????????????????????????
???????????????????????????????
??????????????????A???????A??????...

1 ?
2515?101865??14?5??6?:T 11 L 2 22?88%?3?12%????100%;????????50?
2
2.1 ? ??????????????????????a?????????????????
2.2 ? ????????????????????????;?????????????
2.3 ?? ????????????? 1 ??????????????????????????????????? 2 ?????6?
2.4 ???? ???????????????????????R????????????
2.5 ???? ?v????...

?:??
1
2
3 ?
4 ??
?
1 ?
2 ?
3 ??????
4 ??
????????????????????????????????????h???????????????????????????????????????????????????
?????????????????????????????
???????46?????????

???????????????

?????????????
??????2760m???,??12???????
,?715??????????????
??
???36???2546m??1???1620
????????...

?


Down\'s??????????135???????B??-????

21-?(trisomy2lsyndrome)???;??21???1846Sequin??1866Down???Down\'s?1959Lejeune??21???19601961LejeuneClarke????????:21-???????????????M?0.32~3%?0.56~0.64%
:???3:2
[?] ???????I????I????????????(??????????????)??????20~29????0.62~0.88?30~39?1.06~3.74?40~49
?9....

????????????????????

1???????????????????
2??????????????????? ???????????????

3??????????????????????????????????????????????????????N???

4??????????????36?????

5???????????????????????

6???????????????????????

???????????????????????
????????10??12?????????????????

???

???12??????...