Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Department of Biotechnology, Asia University, Taichung, Taiwan; School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; Institute of Clinical and Community Health Nursing, National Yang-Ming University, Taipei, Taiwan; Department of Obstetrics and Gynecology, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
Department of Obstetrics and Gynecology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
Taiwan J Obstet Gynecol. 2020 Mar;59(2):301-305. doi: 10.1016/j.tjog.2020.01.021.
We present prenatal diagnosis low-level mosaic trisomy 17 with maternal uniparental disomy (UPD) 17 at amniocentesis in a pregnancy with a favorable outcome.
A 40-year-old, primigravid woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age. This pregnancy was conceived by in vitro fertilization and embryo transfer. Amniocentesis revealed a karyotype of 47,XX,+17 [13]/ 46, XX [23]. Repeat amniocentesis was performed at 21 weeks of gestation. Conventional cytogenetic analysis was applied on cultured amniocytes, parental bloods and cord blood. Simultaneous molecular genetic analysis such as interphase fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH) and quantitative fluorescent polymerase chain reaction (QF-PCR) assays were applied on uncultured amniocytes. Interphase FISH was applied on postnatal buccal cells.
Repeat amniocentesis revealed a karyotype of 47,XX,+17[6]/46,XX[28]. Genetic analyses on uncultured amniocytes showed the results of mosaic trisomy 17 (12/101 cells = 11.9%) in FISH analysis, no genomic imbalance in aCGH analysis and maternal UPD 17 in QF-PCR assays. The parental karyotypes were normal. Prenatal ultrasound findings were unremarkable. The parents decided to continue the pregnancy, and a 1449-g, phenotypically normal female baby was delivered prematurely at 31 weeks of gestation. The cord blood had a karyotype of 46,XX. She had a normal psychomotor development at age 22 months at follow-up. Interphase FISH analysis on buccal cells showed trisomy 17 signals in 1/66 cells (1.5%).
Low-level mosaicism for trisomy 17 associated with maternal UPD 17 detected by amniocentesis without ultrasound abnormality can be associated with a favorable outcome. Molecular genetic analysis of uncultured amniocytes at repeat amniocentesis is useful for confirmation and genetic counseling under such as circumstance.
我们介绍了一例经羊膜穿刺术诊断的低水平嵌合体 17 三体，伴有母源单亲二体 17（UPD17），该妊娠结局良好。
一位 40 岁的初产妇因高龄接受羊膜穿刺术，该妊娠通过体外受精和胚胎移植受孕。羊膜穿刺术显示核型为 47，XX，+17 [13]/46，XX [23]。妊娠 21 周时再次行羊膜穿刺术。对培养的羊水细胞、父母血液和脐带血进行常规细胞遗传学分析，对未培养的羊水细胞进行间期荧光原位杂交（FISH）、阵列比较基因组杂交（aCGH）和定量荧光聚合酶链反应（QF-PCR）等同时进行分子遗传学分析。对产后口腔颊细胞进行间期 FISH。
再次羊膜穿刺术显示核型为 47，XX，+17[6]/46，XX[28]。对未培养的羊水细胞进行遗传分析显示，FISH 分析结果为嵌合体 17 三体（12/101 细胞=11.9%），aCGH 分析未见基因组失衡，QF-PCR 分析显示母源 UPD17。父母的核型均正常。产前超声检查未见异常。父母决定继续妊娠，一名 1449 克、表型正常的女婴于妊娠 31 周早产。脐带血核型为 46，XX。随访时，患儿 22 个月时精神运动发育正常。口腔颊细胞间期 FISH 分析显示 1/66 细胞（1.5%）存在 17 三体信号。
在无超声异常的情况下，通过羊膜穿刺术检测到的低水平嵌合体 17 三体伴母源 UPD17 可能与良好的妊娠结局相关。在这种情况下，重复羊膜穿刺术时对未培养羊水细胞进行分子遗传学分析有助于确认和遗传咨询。
