Genetic identification of pregnancies responsible for choriocarcinomas after multiple pregnancies by restriction fragment length polymorphism analysis.

The pregnancies responsible for two cases of choriocarcinomas were determined by the restriction fragment length polymorphism of human leukocyte antigen-DQ genes in the tumors and leukocytes from the patients, their husbands, and their children. The first case was preceded by three normal pregnancies, and the second case was preceded by two normal pregnancies and a complete hydatidiform mole. Comparison of the restriction fragment length polymorphism patterns revealed that the first case of choriocarcinoma carried the parental genome and originated from the third normal pregnancy, whereas the second case was of androgenetic origin from the complete mole. By choosing an appropriate probe (or probes), restriction fragment length polymorphism analysis is shown to be a useful method for identification of the pregnancy responsible for choriocarcinoma.