目的 探讨1q21.1微缺失/微重复综合征胎儿的临床表型、遗传咨询、妊娠结局及远期发育情况，构建该拷贝数变化胎儿全面的临床图景，为临床决策提供参考与依据。方法 回顾性分析2017年1月至2022年12月，符合产前诊断指征并行羊水染色体核型分析和染色体拷贝数变异检测的孕妇资料。结果 共纳入1q21.1微缺失/微重复综合征胎儿39例，检出率0.16%（39/24240）。拷贝数变异片段大小范围为0.24 Mb~62.34 Mb，其中22例（56.4%）为1q21.1微缺失，17例（43.6%）为1q21.1微重复。22例1q21.1微缺失胎儿中10例产前超声异常（10/22，45.6%），4例无创/血清学筛查高风险（4/22，18.2%），5例高龄（5/22，22.7%），3例有不良孕产史（3/22，13.6%）。缺失病例中6例行亲本溯源检测显示新发变异2例，父源性3例，母源性1例。17例1q21.1微重复胎儿中8例产前超声异常（8/17，45.6%），4例无创/血清学筛查高风险（5/17，29.4%），5例高龄（2/17，11.8%），3例有不良孕产史（3/17，17.6%）。重复病例中仅1例行亲代溯源检测显示为新发变异。结论 1q21.1微缺失/微重复在胎儿期的表现多样，CNV-seq技术对包括1q21.1在内的染色体微缺失/微重复综合征胎儿检出具有重要价值。

Objective To investigate the clinical phenotype, genetic counseling, pregnancy outcomes, and long-term developmental outcomes of fetuses with 1q21.1 microdeletion/ microduplication syndrome, and to provide a comprehensive clinical picture of fetuses with this copy number variation to inform clinical decision-making. Methods A retrospective analysis was conducted of pregnant women from January 2017 to December 2022. Results 39 cases of 1q21.1 microdeletion/microduplication syndrome fetuses were identified, with a detection rate of 0.16% (39/24,240). The size range of the copy number variation segments was 0.24 Mb to 62.34 Mb, with 22 cases (56.4%) being 1q21.1 microdeletions and 17 cases (43.6%) being 1q21.1 microduplications. Among the 22 cases of 1q21.1 microdeletion fetuses, 10 had prenatal ultrasound abnormalities (10/22, 45.6%), 4 had high-risk non-invasive/serological screening results (4/22, 18.2% ), 5 cases were of advanced maternal age (5/22, 22.7%), and 3 cases had a history of adverse pregnancy outcomes (3/22, 13.6%); among the deletion cases, 6 underwent parental origin testing, revealing 2 de novo mutations, 3 paternal origin, and 1 maternal. Among the 17 cases of 1q21.1 microduplication fetuses, 8 had prenatal ultrasound abnormalities (8/17, 45.6%), 4 had high-risk non-invasive/serological screening results (5/17, 29.4%), 5 were of advanced maternal age (2/17, 11.8%), and 3 had a history of adverse pregnancy outcomes (3/17, 17.6%); among the repeat cases, only 1 case showed a de novo mutation after parental lineage tracing. Conclusion 1q21.1 microdeletions/microduplications exhibit diverse manifestations during fetal development. CNV-seq technology holds significant value for detecting fetal cases of chromosomal microdeletion/microduplication syndromes, including 1q21.1.