A reliable assay for rapidly defining transplacental metastasis using quantitative PCR

To choose the most appropriate treatment for children affected by a transplacental metastasis, it is crucial to ascertain the maternal origin of the tumor. Up-to-date conclusive diagnosis is generally achieved through fluorescence in situ hybridization or karyotyping analysis. Herein, we report an alternative, reliable assay for rapidly defining vertical cancer transmission to the fetus by using quantitative polymerase chain reaction. Our assay indicates that quantification of the copy number of the sex chromosomes by specific short tandem repeats markers, in genomic DNA purified from the tumor biopsy cells, could be used to correctly evaluate transplacental metastasis events.