Prenatal application of fluorescent in situ hybridization (FISH) for identification of a mosaic Y-chromosome marker, idic(Yp).
An amniocentesis was performed at 13.3 weeks' gestation for advanced maternal age. A mosaic sex chromosome pattern was found: of 50 cells examined, 34 had a 45,X karyotype. In 14 cells with a modal number of 46, a recognizable Y was substituted by a small non-fluorescent marker. C-banding identified the marker as an isodicentric in 12 cells. In two cells, the non-fluorescent marker appeared to be monocentric and looked like a non-fluorescent del (Yq), but could have been an isodicentric Y with inactivation of one of the centromeres. Two cells with a modal number of 47 showed two copies of the monocentric marker. Fluorescent in situ hybridization with an alpha satellite Y-specific centromeric probe confirmed the Y-chromosome origin of the markers and allowed for more accurate prenatal diagnostic information.
Bernstein
R
R
Department of Pediatrics, College of Medicine, University of California, Irvine.
Steinhaus
K A
KA
Cain
M J
MJ
D000328:Adult; D000649:Amniocentesis; D002503:Centromere / Q000648:ultrastructure; D002869:Chromosome Aberrations; D004276:DNA, Satellite / Q000032:analysis; D005260:Female; D005456:Fluorescent Dyes; D006801:Humans; D017403:In Situ Hybridization / Q000379:methods*; D007621:Karyotyping; D009030:Mosaicism; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D014998:Y Chromosome / Q000648:ultrastructure*
D004276:DNA, Satellite; D005456:Fluorescent Dyes