Genotyping of suspected partial hydatidiform moles - our experiences and future directions

This brief research report summarizes our experience with the molecular differential diagnosis of clinically or pathologically suspected partial hydatidiform moles and discusses practical diagnostic options when economic resources or laboratory infrastructure are limited. We analyzed the genome composition of 68 suspected cases using short tandem repeat genotyping based on quantitative fluorescent PCR and fragmentation analysis. Genetic testing excluded a partial mole in 35 cases (51%) by demonstrating a diploid or monogynic monoandric diploid genome, while in 33 cases (49%) a partial mole was confirmed through identification of diandric triploidy (31 cases) or triandric tetraploidy (2 cases). No instances of digynic triploidy were detected in this cohort. Our findings indicate that, in the absence of access to a DNA laboratory, most suspected partial moles can still be accurately evaluated using ploidy assessment by more widely available methods, such as fluorescent in situ hybridization, DNA flow cytometry, or conventional karyotyping, given the apparent rarity of digynic triploidy among these cases.