Zhang, Zhi-TaoQi, Wen-XuLiu, Cai-XiaYin, Shao-WeiZhao, YanLi-Ling, JesseLv, Yuan2020-11-182020-11-182019-02Zhang Zhi-Tao, Qi Wen-Xu, Liu Cai-Xia, Yin Shao-Wei, Zhao Yan, Li-Ling Jesse, Lv Yuan. A small supernumerary marker chromosome resulting in mosaic partial tetrasomy 4q26-q31.21 in a foetus with multiple congenital malformations. Journal of Genetics. 2019 Feb; 98: 1-40022-13330973-7731http://imsear.searo.who.int/handle/123456789/215477A parental diagnosis was performed for an unborn foetus of a healthy couple, who was due for ultrasound detection of multiple malformations and abnormal amniotic fluid karyotypes. For an accurate diagnosis, routine G-banding analysis and nextgeneration sequencing (NGS)were carried out. Finally, conventional cytogenetic analysis suggested that the foetus had a karyotype of47,XX,+mar[52]/46,XN,meanwhileNGSalso revealed a partial tetrasomy of 27.84Mbfrom4q26-q31.21 (117,385,735–145,225,759), and G-banding analysis excluded the couple to have carried the 4q26-q31.21 duplication. We have identified a de novo mosaic small supernumerary marker chromosomes (sSMC) derived from 4q26-q31.21 in a foetus with hemivertebra, polydactyly, abnormal ears, and heart and ventricular septal defect.hemivertebrapolydactylyventricular septal defectabnormal ears.Journal ArticleIndiaLiaoning Centre for Prenatal Diagnosis, Department of Gynecology and Obstetrics, Shengjing Hospital Affiliated to China Medical University, Shenyang 110004, People’s Republic of ChinaDepartment of Radiology, Shengjing Hospital Affiliated to ChinaMedical University, Shenyang 110004, People’s Republic of ChinaGenetics Unit, Shenyang Maternity and Infant’s Hospital, Shenyang 110005, People’s Republic of ChinaJinxin Research Institute of Reproductive Medicine and Genetics, Jinjiang Maternal and Children’s Health Care Hospital, Chengdu 610041, People’s Republic of China