Fetal t(5p;21q) misdiagnosed as monosomy 21: A plea for in situ hybridization studies

Abstract

We report a case of 45,XY,-5,-21,+der (5) t(5;21) (p13 or p14;q11.2 or q21) that was prenatally misdiagnosed as complete monosomy 21 and terminated at 24 weeks of gestation. Subsequent fluorescence in situ hybridization studies with a chromosome 21 painting probe documented the cryptic unbalanced translocation.