RT Book, Section
A1 McCarthy, Jeanette J.
A1 Mendelsohn, Bryce A.
SR Print(0)
ID 1134734762
T1 Pregnancy
T2 Precision Medicine: A Guide to Genomics in Clinical Practice
YR 2016
FD 2016
PB McGraw-Hill Education
PP New York, NY
SN 9781259644139
LK accessmedicine.mhmedical.com/content.aspx?aid=1134734762
RD 2024/04/19
AB For  decades,  the  only  application  of  genetic  screening  that  most  individuals  would  ever  encounter  was  testing  for  aneuploidies  in  pregnant  women,  particularly  those  over  age  35.  The  risk  of  a  fetus  being  affected  by  Trisomy  21  (discussed  as  a  clinical  entity  in  Chapter  3)  increases  gradually  as  a  woman  ages,  and  35  was  somewhat  arbitrarily  selected  as  the  age  at  which  the  risk  of  Trisomy  21  was  sufficiently  high  to  justify  testing  by  amniocentesis  or  chorionic  villus  sampling  (CVS),  each  of  which  carries  with  it  a  very  small  risk  of  miscarriage  or  other  fetal  complications.  However,  the  majority  of  children  with  Trisomy  21  are  born  to  women  younger  than  35,  simply  because  younger  women  have  disproportionately  more  children  than  their  reduced  risk  for  Trisomy  21.