Pallister-Killian syndrome (tetrasomy 12p) is an uncommon aneuploidy, which
may present in the prenatal period with an ultrasonographically detected f
etal abnormality or following karyotyping for maternal age. We report a cas
e that presented with increased nuchal translucency and hydrops at a first
trimester screening scan for trisomy 21. Copyright (C) 2000 John Wiley & So
ns, Ltd.