Zhou Lili, Zheng Zhaoke, Xu Yunzhi, Lv Xiaoxiao, Xu Chenyang, Xu Xueqin
Center of Prenatal Diagnosis, Wenzhou Central Hospital, Wenzhou, 325000, People's Republic of China.
Mol Cytogenet. 2021 Mar 19;14(1):19. doi: 10.1186/s13039-021-00537-2.
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.
单亲二体（UPD）的表型具有多样性，可能无临床影响，也可能导致临床体征和症状。分子分析对于做出正确诊断至关重要。本研究对4512例产前诊断样本进行回顾性分析，使用单核苷酸多态性（SNP）芯片探讨UPD的分子特征和产前表型。
在4512例样本中，共检测到7例UPD，总发生率为0.16%。在这7例UPD中，2例与染色体畸变相关（2/7），4例（4/7）超声检查结果异常。1例为同二体UPD（14），2例为杂合/同二体混合UPD（15），经甲基化特异性多重连接依赖探针扩增（MS-MLPA）证实为与普拉德-威利综合征（PWS）相关的母源UPD（15）。4例分别为染色体1、3、14和16的同二体UPD；这与单体拯救机制一致。另外3例杂合/同二体混合UPD与三体拯救机制一致。
UPD的产前表型具有多样性，分子分析对于UPD的正确诊断和遗传咨询至关重要。SNP芯片在UPD产前诊断病例中是一种有用的基因检测方法。
