目的:我们介绍了羊膜腔穿刺术中的马赛克四体9p与胎儿结局良好相关的妊娠,围产期非整倍体细胞系的逐渐减少和各种组织中的细胞遗传学差异。
方法:一名33岁的初产妇因焦虑在妊娠18周时接受了选择性羊膜穿刺术,培养的羊膜细胞核型为47,XX,+i(9)(p10)[20]/46,XX[55]。妊娠20周时进行了阴道穿刺术,脐带血核型为47,XX,+i(9)(p10)[7]/46,XX[15]。她在妊娠23周时被转介接受遗传咨询,重复羊膜穿刺术显示核型为47,XX,+i(9)(p10)[1]/46,XX[16],在培养的羊膜细胞中具有四体9p的一个集落中有七个细胞,在未培养的羊膜细胞中,定量荧光聚合酶链反应(QF-PCR)分析排除了单亲二体(UPD)9和确定的父系起源的额外i(9p),对从未培养的羊膜细胞提取的DNA进行的阵列比较基因组杂交(aCGH)分析显示,ARR9p24.3p13.1×3.0与四体9p的50%镶嵌性一致,未培养的羊膜细胞上的间期荧光原位杂交(FISH)显示,四体9p的镶嵌性为22.6%(12/53细胞)。妊娠27周时的第三次羊膜穿刺术显示培养的羊膜细胞的核型为46,XX(10/10菌落),未培养的羊膜细胞的间期FISH分析显示,四体9p具有20%(20/100细胞)的镶嵌性。亲本核型和产前超声检查正常。妊娠39周时,一名表型正常的3388-g女婴分娩。脐带血的核型,脐带和胎盘分别为47,XX,+idic(9)(q12)[19]/46,XX[21]或47,XX,+idic(9)(pter→q12:q12→pter)[19]/46,XX[21],47,XX,+idic(9)(q12)[1]/46,XX[39]和47,XX,+idic(9)(q12)[4]/46,XX[36],分别。当在两个月的年龄进行随访时,新生儿表型正常,外周血核型为47,XX,+idic(9)(q12)[18]/46,XX[22],对100个口腔粘膜细胞进行的间期FISH分析显示,四体9p具有1%(1/100细胞)的镶嵌性。在7个月大的时候进行随访,新生儿表型正常,外周血核型为47,XX,+idic(9)(q12)[14]/46,XX[26]。
结论:羊膜穿刺术中的马赛克四体9p可能是一种短暂的良性疾病,并且可能与有利的胎儿结局和围产期非整倍体细胞系的逐渐减少以及各种组织中的细胞遗传学差异有关。
OBJECTIVE: We present mosaic tetrasomy 9p at amniocentesis in a pregnancy associated with a favorable fetal outcome, perinatal progressive decrease of the aneuploid cell line and cytogenetic discrepancy in various tissue.
METHODS: A 33-year-old primigravid woman underwent elective amniocentesis at 18 weeks of gestation because of anxiety, and the karyotype of cultured amniocytes was 47,XX,+i (9) (p10)[20]/46,XX [55]. Cordocentesis was performed at 20 weeks of gestation, and the karyotype of cord blood was 47,XX,+i (9) (p10)[7]/46,XX [15]. She was referred for genetic counseling at 23 weeks of gestation, and repeat amniocentesis revealed a karyotype of 47,XX,+i (9) (p10)[1]/46,XX [16] with seven cells in one colony having tetrasomy 9p in cultured amniocytes, and in uncultured amniocytes, quantitative fluorescence polymerase chain reaction (QF-PCR) analysis excluded uniparental disomy (UPD) 9 and determined paternal origin of the extra i (9p), array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed arr 9p24.3p13.1 × 3.0 consistent with 50% mosaicism for tetrasomy 9p, and interphase fluorescence in situ hybridization (FISH) on uncultured amniocytes showed 22.6% (12/53 cells) mosaicism for tetrasomy 9p. A third amniocentesis at 27 weeks of gestation revealed a karyotype of 46, XX (10/10 colonies) in cultured amniocytes, and interphase FISH analysis on uncultured amniocytes revealed 20% (20/100 cells) mosaicism for tetrasomy 9p. The parental karyotypes and prenatal ultrasound were normal. At 39 weeks of gestation, a phenotypically normal 3388-g female baby was delivered. The karyotypes of cord blood, umbilical cord and placenta were 47,XX,+idic (9) (q12)[19]/46,XX [21] or 47,XX,+idic (9) (pter→q12:q12→pter)[19]/46,XX [21], 47,XX,+idic (9) (q12)[1]/46,XX [39] and 47,XX,+idic (9) (q12)[4]/46,XX [36], respectively. When follow-up at age two months, the neonate was phenotypically normal, the peripheral blood had a karyotype of 47,XX,+idic (9) (q12)[18]/46,XX [22], and interphase FISH analysis on 100 buccal mucosal cells revealed 1% (1/100 cells) mosaicism for tetrasomy 9p. When follow-up at age seven months, the neonate was phenotypically normal, and the peripheral blood had a karyotype of 47,XX,+idic(9)(q12)[14]/46,XX[26].
CONCLUSIONS: Mosaic tetrasomy 9p at amniocentesis can be a transient and benign condition, and can be associated with a favorable fetal outcome and perinatal progressive decrease of the aneuploid cell line and cytogenetic discrepancy in various tissue.