Genesis and systematization of cardiovascular anomalies in murine trisomy 16.

On account of genetic homologies trisomy 16 in the mouse is regarded as an animal model of Down's syndrome. A detailed evaluation of the cardiovascular system in 109 fetuses with trisomy 16 and 422 balanced siblings was performed in order to systematize the cardiovascular anomalies and to elucidate the pathogenetic mechanisms responsible for their formation. 92% of fetuses with experimentally induced trisomy 16 exhibited cardiovascular anomalies. The most common types of anomalies were hypoplasia and aplasia of the aortic arch, which appeared in 85% of the fetuses. Situs inversus of the aortic arch system was remarkably frequent (20%). Hypoplasia or aplasia of the pulmonary artery was seen in 10% of the fetuses. A too proximal insertion of the pulmonary artery into the ascending aorta was observed in 8% of the fetuses.