TY  - CHAP
M1  - Book, Section
TI  - 47,XXY (Klinefelter Syndrome)
A1  - Bianchi, Diana W.
A1  - Crombleholme, Timothy M.
A1  - D'Alton, Mary E.
A1  - Malone, Fergal D.
PY  - 2015
T2  - Fetology: Diagnosis and Management of the Fetal Patient, 2e
AB  - Key  PointsResults  from  meiotic  nondisjunction  that  occurs  in  the  sperm  (44%  of  cases)  or  egg  (56%  of  cases).About  10%  of  all  cases  are  diagnosed  prenatally  and  26%  of  cases  are  diagnosed  postnatally.  The  majority  of  cases  are  never  diagnosed,  which  suggests  that  symptoms  are  mild.Incidence  of  47,  XXY  is  1  in  500  to  1  in  800  male  births.  Incidence  of  48,  XXXY  is  1  in  20,000.No  sonographic  findings  are  characteristic.  Nuchal  translucency  measurement  may  be  increased.The  most  significant  factors  regarding  the  decision  whether  or  not  to  terminate  the  affected  pregnancy  are  the  presence  of  sonographic  abnormalities  and  the  medical  specialty  of  the  person  providing  the  genetic  counseling.Affected  males  are  tall,  but  phenotypically  normal,  with  an  increased  risk  for  developmental  delays  in  speech,  neuromotor,  and  learning  disabilites.Testosterone  treatment  is  recommended,  beginning  at  puberty.50%  to  80%  of  affected  males  develop  gynecomastia,  but  it  is  usually  mild.Fertility  is  now  possible  with  assisted  reproductive  technology.Motor  impairment  and  speech  and  language  problems  are  more  common  if  the  extra  X  chromosome  is  paternally  derived.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/18
UR  - obgyn.mhmedical.com/content.aspx?aid=1106402152
ER  -