Chen Chih-Ping, Lin Shuan-Pei, Lin Yi-Hui, Chern Schu-Rern, Wu Peih-Shan, Chen Yen-Ni, Chen Shin-Wen, Yang Chien-Wen, Chen Wen-Lin, Wang Wayseen
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 Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan; Department of Pediatrics, MacKay Memorial Hospital, Taipei, Taiwan; Department of Early Childhood Care, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan.
Taiwan J Obstet Gynecol. 2016 Dec;55(6):852-855. doi: 10.1016/j.tjog.2016.08.002.
We present molecular cytogenetic characterization of mosaicism for a small supernumerary marker chromosome (sSMC) derived from chromosome 8.
A 35-year-old woman underwent amniocentesis at 16 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 47,XY,+mar[20]/46,XY[39]. However, array comparative genomic hybridization analysis on the subcultured amniocytes revealed no genomic imbalance. Prenatal ultrasound showed bilateral ventriculomegaly, intrauterine growth restriction, and an enlarged right atrium. At 36 weeks of gestation, a 2380-g baby was delivered with mild facial dysmorphism. The baby postnatally manifested right hydronephrosis, vesicoureteral reflux, hypospadias, hypotonia, strabismus, developmental delay and mild mental retardation. Array comparative genomic hybridization and metaphase fluorescence in situ hybridization analyses were performed on the peripheral blood to determine the origin and mosaicism of the sSMC, and quantitative fluorescent polymerase chain reaction was used to exclude uniparental disomy.
The blood had a karyotype of 47,XY,+mar[17]/46,XY[23]. Array comparative genomic hybridization revealed arr 8p12q13.1 (33,476,753-67,428,722)×2.40 (Log2 ratio=0.24) encompassing 98 Online Mendelian Inheritance in Man (OMIM) genes including CHD7, consistent with 30-40% mosaicism for r(8)(::p12→q13.1::). Metaphase fluorescence in situ hybridization identified the sSMC(8) in 21/33 of cultured lymphocytes. Quantitative fluorescent polymerase chain reaction excluded uniparental disomy 8.
Mosaic sSMC(8) derived from r(8)(::p12→q13.1::) can present phenotypic abnormalities. Chromosome 8q12 duplication syndrome should be included in differential diagnosis when an sSMC(8) contains 8q12.2 and CHD7.
我们展示了源自8号染色体的小额外标记染色体（sSMC）的嵌合体的分子细胞遗传学特征。
一名35岁女性因母亲年龄较大，在妊娠16周时接受了羊膜穿刺术。羊膜穿刺术显示核型为47,XY,+mar[20]/46,XY[39]。然而，对传代培养的羊水细胞进行的阵列比较基因组杂交分析未发现基因组失衡。产前超声显示双侧脑室扩大、宫内生长受限和右心房增大。妊娠36周时，分娩出一名体重2380克的婴儿，面部有轻度畸形。该婴儿出生后表现为右肾积水、膀胱输尿管反流、尿道下裂、肌张力低下、斜视、发育迟缓及轻度智力障碍。对其外周血进行了阵列比较基因组杂交和中期荧光原位杂交分析，以确定sSMC的起源和嵌合情况，并使用定量荧光聚合酶链反应排除单亲二体。
血液核型为47,XY,+mar[17]/46,XY[23]。阵列比较基因组杂交显示arr 8p12q13.1（33,476,753 - 67,428,722）×2.40（Log2比值 = 0.24），包含98个《人类孟德尔遗传在线》（OMIM）基因，包括CHD7，与r(8)(::p12→q13.1::)的30 - 40%嵌合情况一致。中期荧光原位杂交在21/33的培养淋巴细胞中鉴定出sSMC(8)。定量荧光聚合酶链反应排除了8号染色体单亲二体。
源自r(8)(::p12→q13.1::)的嵌合性sSMC(8)可表现出表型异常。当sSMC(8)包含8q12.2和CHD7时，8号染色体q12重复综合征应纳入鉴别诊断。
