Molecular identification of a partial hydatidiform mole.

Specimens of a vacuum curettage were microscopically indicated for a hydatidiform mole. The combination of three different approaches identified the specimen as a partial mole caused by the fertilization of a haploid ovum by sperm containing a haploid or diploid nucleus with one or two sets of paternal genetic material. Interphase fluorescence in situ hybridization identified three chromosome 1 centromeres, and DNA flow cytometry revealed a peak with a DNA index of 1.50. The combination of flow cytometric cell sorting and microsatellite marker polymerase chain reaction proved that in this case two alleles were from paternal origin. Because it is known that partial hydatidiform moles have a tendency for recurrence, specimens from the same patient of an earlier executed vacuum curettage were investigated. Microdissection of the villi was performed before DNA isolation in this case as too few villi were present for DNA flow cytometry and cell sorting. In this case, no evidence was fond for additional alleles. This study shows the diagnostic potential of microsatellite markers for genetic typing of hydatidiform moles.