Ying Zhou, Lingling Xu, Lulu Yan, Changshui Chen, Haibo Li
{"title":"[Prenatal diagnosis of a fetus with mosaicism ring chromosome 2].","authors":"Ying Zhou, Lingling Xu, Lulu Yan, Changshui Chen, Haibo Li","doi":"10.3760/cma.j.cn511374-20240313-00172","DOIUrl":null,"url":null,"abstract":"<p><strong>Objective: </strong>To explore the genetic basis for a fetus with increased risk for Down syndrome and cardiac anomalies discovered by prenatal ultrasonography.</p><p><strong>Methods: </strong>A pregnant woman presented at the Women and Children's Hospital of Ningbo University on August 21, 2023 were selected as the study subject. Clinical data were retrospectively analyzed. Maternal peripheral blood sample was collected for non-invasive prenatal testing (NIPT) based on fetal free DNA. Amniotic fluid sample was collected for G-banded chromosomal karyotyping analysis. Trio-whole exome sequencing (WES) was also carried out on the amniotic fluid sample and peripheral blood samples from the couple. Copy number variation (CNV) identified by the WES was validated by real-time fluorescent quantitative PCR (qPCR). Chromosomal karyotyping was also carried out for the couple. This study has been approved by the Medical Ethics Committee of Women and Children's Hospital of Ningbo University (No. EC2020-048).</p><p><strong>Results: </strong>Ultrasound examination at 22<sup>+6</sup> gestational weeks had indicated intrauterine growth retardation (IUGR). The fetus was also found to have ventricular septal defect, overriding aorta and pulmonary stenosis. NIPT indicated a low risk for aneuploidy of chromosomes 13, 18 and 21. G-banding analysis revealed that the fetus had a karyotype of 45,XY,-2[5]/46,XY,r(2)(p25q37)[55]. WES has identified a deletion of approximately 1 614.28 kb in the 2p25.3 region, namely seq[hg38]del(2)(p25.3p25.3)chr2: g.10500_1624775del. The same deletion was found in neither parent, suggesting a de novo origin. qPCR results confirmed the expression of target genes in the fetal sample to be significantly reduced, whilst no similar anomaly was found in either parent.</p><p><strong>Conclusion: </strong>The mosaicism ring chromosome 2 probably underlay the IUGR and cardiovascular malformations in this fetus.</p>","PeriodicalId":39319,"journal":{"name":"中华医学遗传学杂志","volume":"41 11","pages":"1356-1362"},"PeriodicalIF":0.0000,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"中华医学遗传学杂志","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.3760/cma.j.cn511374-20240313-00172","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Medicine","Score":null,"Total":0}
引用次数: 0
Abstract
Objective: To explore the genetic basis for a fetus with increased risk for Down syndrome and cardiac anomalies discovered by prenatal ultrasonography.
Methods: A pregnant woman presented at the Women and Children's Hospital of Ningbo University on August 21, 2023 were selected as the study subject. Clinical data were retrospectively analyzed. Maternal peripheral blood sample was collected for non-invasive prenatal testing (NIPT) based on fetal free DNA. Amniotic fluid sample was collected for G-banded chromosomal karyotyping analysis. Trio-whole exome sequencing (WES) was also carried out on the amniotic fluid sample and peripheral blood samples from the couple. Copy number variation (CNV) identified by the WES was validated by real-time fluorescent quantitative PCR (qPCR). Chromosomal karyotyping was also carried out for the couple. This study has been approved by the Medical Ethics Committee of Women and Children's Hospital of Ningbo University (No. EC2020-048).
Results: Ultrasound examination at 22+6 gestational weeks had indicated intrauterine growth retardation (IUGR). The fetus was also found to have ventricular septal defect, overriding aorta and pulmonary stenosis. NIPT indicated a low risk for aneuploidy of chromosomes 13, 18 and 21. G-banding analysis revealed that the fetus had a karyotype of 45,XY,-2[5]/46,XY,r(2)(p25q37)[55]. WES has identified a deletion of approximately 1 614.28 kb in the 2p25.3 region, namely seq[hg38]del(2)(p25.3p25.3)chr2: g.10500_1624775del. The same deletion was found in neither parent, suggesting a de novo origin. qPCR results confirmed the expression of target genes in the fetal sample to be significantly reduced, whilst no similar anomaly was found in either parent.
Conclusion: The mosaicism ring chromosome 2 probably underlay the IUGR and cardiovascular malformations in this fetus.
期刊介绍:
Chinese Journal of Medical Genetics is a medical journal, founded in 1984, under the supervision of the China Association for Science and Technology, sponsored by the Chinese Medical Association (hosted by Sichuan University), and is now a monthly magazine, which attaches importance to academic orientation, adheres to the scientific, scholarly, advanced, and innovative, and has a certain degree of influence in the industry.
Chinese Journal of Medical Genetics is a journal of Peking University, and is now included in Peking University Journal (Chinese Journal of Humanities and Social Sciences), CSCD Source Journals of Chinese Science Citation Database (with extended version), Statistical Source Journals (China Science and Technology Dissertation Outstanding Journals), Zhi.com (in Chinese), Wipu (in Chinese), Wanfang (in Chinese), CA Chemical Abstracts (U.S.), JST (Japan Science and Technology Science and Technology), and JST (Japan Science and Technology Science and Technology Research Center). ), JST (Japan Science and Technology Agency), Pж (AJ) Abstracts Journal (Russia), Copernicus Index (Poland), Cambridge Scientific Abstracts, Abstracts and Citation Database, Abstracts Magazine, Medical Abstracts, and so on.