目的·探讨无创产前检测（non-invasive prenatal testing，NIPT）对染色体17p12区域［包含外周髓鞘蛋白22（peripheral myelin protein 22，PMP22）］拷贝数变异（copy number variations，CNVs）的检测效能及临床应用价值。方法·选取2020年7月—2024年4月在上海交通大学医学院附属国际和平妇幼保健院行NIPT的孕妇，统计NIPT结果提示17p12区域微缺失/重复高风险个体的临床资料，随访相关个体后续产前诊断和孕妇夫妻双方外周血染色体微阵列分析（chromosomal microarray analysis，CMA）结果，分析NIPT筛查17p12区域微缺失/重复的阳性预测值及假阳性的原因。对已明确诊断携带17p12区域CNVs的胎儿及孕妇进行追踪随访，记录妊娠结局及相关临床表型。结果·共61 858例孕妇行NIPT，其中24例（0.04%）结果提示17p12区域CNVs高风险，包括17p12微重复高风险6例、17p12微缺失高风险18例。24例孕妇均进行了后续遗传咨询，其中21例（87.50%）进行介入性产前诊断。介入性产前诊断结果提示胎儿17p12重复异常4例、17p12缺失异常9例、未见异常8例，阳性预测值61.90%（13/21）。对8例胎儿假阳性的孕妇外周血行CMA分析，提示孕妇自身均携带17p12区域微缺失/重复。对NIPT提示母源CNVs高风险的孕妇进一步分析提示，孕妇自身均携带相关CNVs。成功随访其中20例孕妇，除1例因胎儿新发17p12区域微重复选择终止妊娠外，其余均正常分娩。正常分娩的胎儿随访至今（平均年龄1.5岁），暂未报告相关异常。对16例携带17p12区域CNVs的孕妇进行评估，有2例表现出与17p12区域CNVs相关的临床表型特征，其余暂未见异常。结论·NIPT对17p12区域CNVs有较好的检测效能，母体CNVs是导致NIPT检测假阳性的主要原因。

Objective ·To evaluate the detection efficacy and clinical value of non-invasive prenatal testing (NIPT) for identifying copy number variations (CNVs) in the recurrent 17p12 region, including the peripheral myelin protein 22 (PMP22) gene. Methods ·Pregnant women who underwent NIPT in the International Peace Maternity & Child Health Hospital, Shanghai Jiao Tong University School of Medicine between July 2020 and April 2024 were enrolled. Clinical data of individuals indicated as high-risk for microdeletions/duplications in the 17p12 region based on NIPT results were collected. Follow-up was conducted to assess the results of subsequent prenatal diagnosis and chromosomal microarray analysis (CMA) performed on peripheral blood from both the pregnant women and their husband. The positive predictive value (PPV) of NIPT for detecting microdeletions/duplications in the 17p12 region, as well as the underlying causes of false positives, was analyzed. Pregnancy outcomes and related clinical phenotypes of fetuses and pregnant women diagnosed with 17p12 CNVs were followed up. Results ·A total of 61 858 pregnant women underwent NIPT testing. NIPT identified 24 cases (0.04%) as high-risk for CNVs in the 17p12 region, including six cases of high-risk 17p12 microduplication and 18 cases of high-risk 17p12 microdeletion. All 24 pregnant women received genetic counseling, and 21 (87.50%) underwent invasive prenatal diagnosis. Invasive prenatal diagnostic confirmed four fetuses with 17p12 microduplications, nine fetuses with 17p12 microdeletions, and eight fetuses with no abnormalities, yielding a PPV of 61.90% (13/21). CMA analysis of maternal peripheral blood in the eight false-positive cases revealed that all mothers carried 17p12 CNVs. Further analysis of pregnant women with NIPT-indicated maternal CNVs revealed that all of them carried relevant CNVs. Among the 20 women with successful follow-up, the majority had normal deliveries, with only one case choosing to terminate the pregnancy due to a de-novo fetal 17p12 microduplication. Normally delivered fetuses (average age: 1.5 years) were followed up without reporting any significant abnormalities. Of the 16 pregnant women carrying 17p12 CNVs, only two exhibited clinical phenotypes associated with these CNVs, while the others remained asymptomatic. Conclusion ·NIPT demonstrates favorable detection efficacy for CNVs in the 17p12 region. Maternal CNVs are the primary cause of false-positive NIPT results for this region.