An abortus with a normal/trisomy 16 mosaicism: instability of trisomic cells in vitro.

A 46,XX/47,XX,+16 mosaicism was demonstrated in cultured chorionic cells obtained from an abortion material. By tracing polymorphic fluorescent chromosome markers in the abortus and the parents, the karyotypically normal component was confirmed to be non-maternal in origin. The trisomic cells showed a growth disadvantage, and were overtaken by the normal cells in prolonged cultivation.