Triploidy is a genetic aberration resulting from an extra haploid set of chromosomes of paternal (diandric) or maternal (digynic) origin. Diandric cases, opposite to digynic ones, may lead to gestational trophoblastic neoplasia (GTN) or generate maternal complications, therefore their identification is crucial, but reproducibility of traditionally used histopathological assessment is poor. The aim of the study was to analyse the usefulness of methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) with probes for two differentially methylated regions (DMR) at chromosome 11p.15.5 for identification of the parental origin of triploidy. 84 triploid DNA samples were tested with MS-MLPA: 34 paternal cases (40.5%) and 50 maternal ones (59.5%) according to the reference results of QF-PCR. Methylation ratio (MR) was calculated. Reference values proposed by the MRC-Holland for diploid samples (MR 0.8–1.2) were used. The values outside these ranges were used to diagnose parental origin of triploidy—paternal (MR > 1.2) or maternal (MR < 0.8). The effectiveness of MS-MLPA was 94.0%. The mean MR in paternal triploidy was 1.7 (SD–0.25; n = 34) compared with 0.56 in maternal triploidy (SD–0.12; n = 50). MR values in paternal and maternal triploidy did not overlap. In five samples (6.0%) parental origin of triploidy could not be accurately established by MS-MLPA, probably due to the maternal cell contamination (MCC). MS-MLPA can be used as a convenient method for distinguishing between paternal and maternal triploidy without the necessity for parental samples testing. It enables adequate selection of the paternal triploid cases for follow up in order to exclude post-molar GTN.

三倍体是遗传的异常，是由父系（双亲）或母体（消化道）来源的额外单倍体染色体组引起的。与强直性病例相反，双性病例可能导致妊娠滋养细胞赘生性肿瘤（GTN）或产生母体并发症，因此对其进行鉴定至关重要，但传统组织病理学评估的可重复性很差。该研究的目的是分析甲基化特异性多重连接依赖探针扩增（MS-MLPA）与11p.15.5染色体上两个差异甲基化区域（DMR）的探针对鉴定三倍体亲本起源的有用性。根据QF-PCR的参考结果，使用MS-MLPA测试了84个三倍体DNA样品：34例父系病例（40.5％）和50例母体病例（59.5％）。计算甲基化率（MR）。使用了MRC-Holland为二倍体样品建议的参考值（MR 0.8-1.2）。这些范围以外的值可用于诊断三倍体的父母起源—父亲（MR> 1.2）或母亲（MR <0.8）。MS-MLPA的有效性为94.0％。父本三倍体的平均MR为1.7（SD–0.25;n  = 34），而母体三倍体为0.56（SD-0.12; n  = 50）。父本和母本三倍体的MR值不重叠。在五个样本（6.0％）中，MS-MLPA无法准确确定三倍体的亲本起源，这可能是由于母体细胞污染（MCC）所致。MS-MLPA可以用作区分父本和母本三倍体的便捷方法，而无需进行父母样本测试。它能够用于以排除后槽牙GTN跟进的父亲三倍体的情况下适当的挑选。