Lo Liang-Ming, Shiau Chii-Shinn, Chen Kuang-Chao, Shaw S W S, Benn Peter
Department of Obstetrics and Gynecology, Taipei Chang Gung Memorial Hospital, Taipei, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Department of Obstetrics and Gynecology, Taipei Chang Gung Memorial Hospital, Taipei, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan; Prenatal Cell and Gene Therapy Group, Institute for Women's Health, University College London, London, UK.
Taiwan J Obstet Gynecol. 2019 Jan;58(1):40-42. doi: 10.1016/j.tjog.2018.11.006.
Non-invasive prenatal testing (NIPT) through the analysis of cell-free DNA in maternal plasma has bee expanded to include clinically-relevant microdeletions such as the 22q11.2 deletion syndrome (22q11.2DS).
We present a pregnancy where the fetus was affected with 22q11.2DS based on chromosome microarray analysis. Discordant results were obtained through two different NIPT methodologies. The pregnancy was identified as high risk by a SNP-based approach but low risk using a genome-wide counting methodology. A review of the technical methods used for these tests provides insight into why they may provide conflicting results and emphasizes the importance of chromosome microarray studies for diagnostic confirmation and defining the deletion.
Currently available NIPT for 22q11.2DS use different technologies that are not equivalent. The genome-wide counting methodology has the potential to detect deletions outside the critical 22q11.2 A-D region but current data suggests it may have a lower sensitivity for deletions within the critical region.
通过分析母血中游离DNA进行的无创产前检测（NIPT）已扩展至包括临床相关的微缺失，如22q11.2缺失综合征（22q11.2DS）。
我们报告一例基于染色体微阵列分析诊断胎儿患有22q11.2DS的妊娠病例。通过两种不同的NIPT方法得出了不一致的结果。基于单核苷酸多态性（SNP）的方法将该妊娠判定为高风险，而采用全基因组计数方法则判定为低风险。对这些检测所使用技术方法的回顾有助于理解为何它们可能给出相互矛盾的结果，并强调了染色体微阵列研究对于诊断确认和明确缺失的重要性。
目前用于22q11.2DS的NIPT采用的不同技术并不等效。全基因组计数方法有可能检测到关键22q11.2 A-D区域以外的缺失，但目前的数据表明其对关键区域内缺失的检测灵敏度可能较低。
