Prenatal diagnosis of trisomy 9.

A male karyotype with trisomy 9 (47,XY,+9) was identified in amniotic fluid cells from a 40-year-old pregnant woman. After termination of the pregnancy by saline abortion, the cytogenetic diagnosis was confirmed in a cell line grown from placental tissue. Microscopic and gross pathological findings in the fetus were compared to 1 case with trisomy 9 and 3 with trisomy 9 mosaicism reported in the literature. A distinct clinical syndrome appears to be associated with this rare autosomal trisomy.