Hydatidiform mole: genetic origin in polyploid conceptuses.

The origin of 29 polyploid conceptuses with villous cystic swelling was examined. One tetraploid specimen showed one maternal and three paternal contributions to the genome. Informative cytogenetic markers in 24 triploids were consistent with fertilization by dispermy. Analysis of cytogenetic markers indicated that polyspermy may account for essentially all polyploid conceptions with an excess of paternal to maternal chromosome complements. The origin of the genome was primarily demonstrated by the study of cytogenetic markers, while HLA determination and enzyme analysis were less informative.