摘要目的:探讨4例单亲二体胎儿的遗传学特征，分析其致病原因和发生机制。方法:选取2021年11月至2024年7月于温州市中心医院接受产前诊断的4个胎儿为研究对象。通过G显带染色体核型、单核苷酸多态性微阵列(SNP-array)及甲基化多重连接探针扩增(MS-MLPA)分析对胎儿进行产前诊断。本研究通过温州市中心医院医学伦理委员会的审查(批件号：L2024-11-028)。结果:4例单亲二体胎儿，分别涉及2、11、15和16号染色体，其中2例合并产前胎儿超声异常，1例血清学筛查提示高风险，1例无创DNA检测提示高风险。1例胎儿染色体核型为45，X？，rob(13；15)(q10；q10)，其父母均为13号和15号染色体罗伯逊易位携带者，其余3例胎儿的染色体核型均正常，染色体核型异常率为25%。家系分析提示3例为父源，1例来源未知。4例致病原因分别是2例印记综合征，1例常染色体隐性遗传病，1例隐匿性嵌合三体。结论:单亲二体临床表型多样，致病原因和发生机制复杂，需联合染色体核型、SNP-array、MS-MLPA等多种技术明确诊断，用以产前遗传咨询和出生后健康管理。

abstractsObjective:To explore the genetic etiology of four fetuses with Uniparental disomy (UPD), and analyze their causes.Methods:Four fetuses undergoing prenatal diagnosis at Wenzhou Central Hospital between November 2021 and July 2024 were selected as the study subjects. Genetic testing and diagnosis were carried out through G-banded chromosomal karyotyping, single nucleotide polymorphism array (SNP-array) and methylation multiplex ligation-dependent probe amplification (MS-MLPA). This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: L2024-11-028).Results:The four cases of pathogenic UPD had involved chromosomes 2, 11, 15 and 16, respectively, of which 2 cases were accompanied by fetal ultrasound abnormalities, One fetus was shown a high risk by serological screening, while another showed a high risk by non-invasive DNA testing. The karyotype of fetus 1 was 45, X?, rob(13; 15)(q10; q10), and its parents had both carried a Robertsonian translocation involving chromosomes 13 and 15, whilst the karyotypes of other three fetuses were all normal. Pedigree analysis indicated that the UPDs in three cases were paternally derived, and the remaining one was unknown. The causes of the four cases included imprinting syndrome in two cases, autosomal recessive disorder in one case, and cryptic mosaic trisomy in one case.Conclusion:The clinical phenotypes of UPD are diverse, and the mechanisms are complex. Combined chromosomal karyotyping, SNP-array, MS-MLPA and other technologies are required to make a clear diagnosis for prenatal genetic counseling and postnatal management.