Prenatal diagnosis of trisomy 21 and X/XX sex chromosome mosaicism

Double aneuploidy involving Down syndrome and Turner syndrome is a rare chromosomal abnormality presumed to occur with a frequency of about 1 in 2 million births. Twenty-one cases of this combined anomaly have been reported and two infants were born with this anomaly after a mistake in prenatal diagnosis. We report the first prenatal diagnosis of Down syndrome combined with Turner mosaicism and suggest that this polysyndrome may be more common than previously estimated. We, therefore, wish to alert cytogenetic laboratories performing prenatal diagnoses of the potential risks of misdiagnosis of this polysyndrome if banding is not performed and if a sufficient number of mitotic cells are not analysed.     

Computed tomographic reconstruction of a fetus with the dysgnathia complex (agnathia-otocephaly)

The dysgnathia complex (agnathia-otocephaly) (AO) is a lethal malformation that consists of congenital absence of the lower jaw with union or close approximation of the lower ears on the front of the neck, microstomia, and hypoglossia. We present a novel case of agnathia-otocephaly with associated organomegaly and the use of postmortem 3-D computed tomographic rendering. Copyright © 2006 John Wiley & Sons, Ltd.