The phenotypes of uniparental disomy (UPD) are variable, which may either have no clinical impact, lead to clinical signs and symptoms. Molecular analysis is essential for making a correct diagnosis. This study involved a retrospective analysis of 4512 prenatal diagnosis samples and explored the molecular characteristics and prenatal phenotypes of UPD using a single nucleotide polymorphism (SNP) array. Out of the 4512 samples, a total of seven cases of UPD were detected with an overall frequency of 0.16%. Among the seven cases of UPD, two cases are associated with chromosomal aberrations (2/7), four cases (4/7) had abnormal ultrasonographic findings. One case presented with iso-UPD (14), and two case presented with mixed hetero/iso-UPD (15), which were confirmed by Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) as maternal UPD (15) associated with Prader-Willi syndrome (PWS). Four cases had iso-UPD for chromosome 1, 3, 14, and 16, respectively; this is consistent with the monosomy rescue mechanism. Another three cases presented with mixed hetero/isodisomy were consistent with a trisomy rescue mechanism. The prenatal phenotypes of UPD are variable and molecular analysis is essential for making a correct diagnosis and genetic counselling of UPD. The SNP array is a useful genetic test in prenatal diagnosis cases with UPD.

中文翻译：

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利用单核苷酸多态性阵列对7例单亲二体性胎儿进行产前诊断

单亲二体性（UPD）的表型是可变的，可能没有临床影响，但会导致临床体征和症状。分子分析对于做出正确的诊断至关重要。这项研究涉及4512产前诊断样本的回顾性分析，并使用单核苷酸多态性（SNP）阵列探讨了UPD的分子特征和产前表型。在4512个样本中，总共检测到7例UPD病例，总频率为0.16％。在7例UPD中，有2例与染色体畸变有关（2/7），有4例（4/7）有异常的超声检查结果。一种情况是使用iso-UPD（14），另一种情况是使用混合异类/ iso-UPD（15），通过甲基化特异性多重连接依赖探针扩增（MS-MLPA）证实，它们是与Prader-Willi综合征（PWS）相关的母体UPD（15）。4例分别具有1、3、14和16号染色体的iso-UPD；这与单体性抢救机制是一致的。另有3例混合异位/等位切开术与三体性抢救机制相符。UPD的产前表型是可变的，分子分析对于正确诊断和诊断UPD至关重要。SNP阵列是用于UPD的产前诊断病例的有用的基因检测。另有3例混合异位/等位切开术与三体性抢救机制相符。UPD的产前表型是可变的，分子分析对于正确诊断和诊断UPD至关重要。SNP阵列是用于UPD的产前诊断病例的有用的基因检测。另有3例混合异位/等位切开术与三体性抢救机制相符。UPD的产前表型是可变的，分子分析对于正确诊断和诊断UPD至关重要。SNP阵列是用于UPD的产前诊断病例的有用的基因检测。