Abstract：
OBJECTIVE: We present low-level mosaic trisomy 9 at amniocentesis in a pregnancy associated with a favorable fetal outcome, intrauterine growth restriction (IUGR), cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes and perinatal progressive decrease of the aneuploid cell line.
METHODS: A 37-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. This pregnancy was conceived by in vitro fertilization and embryo transfer (IVF-ET). Amniocentesis revealed a karyotype of 47,XY,+9[11]/46,XY[32], and simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed arr (X,Y) × 1, (1-22) × 2 without genomic imbalance. Prenatal ultrasound and parental karyotypes were normal. Repeat amniocentesis at 22 weeks of gestation revealed a karyotype of 47,XY,+9[5]/46,XY[19], and simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes revealed arr 9p24.3q34.3 × 2.1 (log2 ratio = 0.1) compatible with 10-15% mosaicism for trisomy 9. Quantitative fluorescence polymerase chain reaction (QF-PCR) assays excluded uniparental disomy (UPD) 9. A third amniocentesis at 29 weeks of gestation revealed a karyotype of 47,XY,+9[5]/46,XY[18], and simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes revealed arr 9p24.3q34.3 × 2.1 (log2 ratio = 0.1) compatible with 10-15% mosaicism for trisomy 9. Interphase fluorescent in situ hybridization (FISH) analysis on uncultured amniocytes revealed 9% (9/100 cells) mosaicism for trisomy 9. IUGR was noted on prenatal ultrasound. The pregnancy was carried to 38 weeks of gestation, and a 2375-g phenotypically normal male baby was delivered. The karyotypes of umbilical cord, cord blood and placenta were 46,XY (40/40 cells), 47,XY,+9[1]/46,XY[39] and 47,XY,+9[12]/46,XY[28], respectively. QF-PCR assays on placenta showed trisomy 9 of maternal origin. When follow-up at age two months, the neonate was normal in development. The peripheral blood had a karyotype of 46,XY (40/40 cells), and the buccal mucosal cells had 7.5% (8/106 cells) mosaicism for trisomy 9 by interphase FISH analysis.
CONCLUSIONS: Low-level mosaic trisomy 9 at amniocentesis can be associated with a favorable fetal outcome and cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes.
METHODS: A 37-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. This pregnancy was conceived by in vitro fertilization and embryo transfer (IVF-ET). Amniocentesis revealed a karyotype of 47,XY,+9[11]/46,XY[32], and simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed arr (X,Y) × 1, (1-22) × 2 without genomic imbalance. Prenatal ultrasound and parental karyotypes were normal. Repeat amniocentesis at 22 weeks of gestation revealed a karyotype of 47,XY,+9[5]/46,XY[19], and simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes revealed arr 9p24.3q34.3 × 2.1 (log2 ratio = 0.1) compatible with 10-15% mosaicism for trisomy 9. Quantitative fluorescence polymerase chain reaction (QF-PCR) assays excluded uniparental disomy (UPD) 9. A third amniocentesis at 29 weeks of gestation revealed a karyotype of 47,XY,+9[5]/46,XY[18], and simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes revealed arr 9p24.3q34.3 × 2.1 (log2 ratio = 0.1) compatible with 10-15% mosaicism for trisomy 9. Interphase fluorescent in situ hybridization (FISH) analysis on uncultured amniocytes revealed 9% (9/100 cells) mosaicism for trisomy 9. IUGR was noted on prenatal ultrasound. The pregnancy was carried to 38 weeks of gestation, and a 2375-g phenotypically normal male baby was delivered. The karyotypes of umbilical cord, cord blood and placenta were 46,XY (40/40 cells), 47,XY,+9[1]/46,XY[39] and 47,XY,+9[12]/46,XY[28], respectively. QF-PCR assays on placenta showed trisomy 9 of maternal origin. When follow-up at age two months, the neonate was normal in development. The peripheral blood had a karyotype of 46,XY (40/40 cells), and the buccal mucosal cells had 7.5% (8/106 cells) mosaicism for trisomy 9 by interphase FISH analysis.
CONCLUSIONS: Low-level mosaic trisomy 9 at amniocentesis can be associated with a favorable fetal outcome and cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes.
摘要：
目的：我们在妊娠羊膜腔穿刺术中呈现低水平镶嵌三体9，与有利的胎儿结局相关，宫内生长受限（IUGR），培养的羊膜细胞和未培养的羊膜细胞之间的细胞遗传学差异以及非整倍体细胞系的围产期逐渐减少。
方法：37岁，由于母亲年龄高，初产妇在妊娠17周时接受了羊膜穿刺术。这种妊娠是通过体外受精和胚胎移植（IVF-ET）设想的。羊膜穿刺术显示核型为47，XY，+9[11]/46,XY[32],并对从未培养的羊膜细胞中提取的DNA进行同步阵列比较基因组杂交（aCGH）分析（X，Y)×1,(1-22)×2无基因组失衡。产前超声和亲本核型正常。在妊娠22周时重复羊膜穿刺术显示核型为47，XY，+9[5]/46,XY[19],同时对从未培养的羊膜细胞中提取的DNA进行aCGH分析，发现arr9p24.3q34.3×2.1（log2比率=0.1）与9三体的10-15％镶嵌性相容。定量荧光聚合酶链反应(QF-PCR)测定排除单亲二体(UPD)9.妊娠29周时的第三次羊膜穿刺术显示核型为47，XY，+9[5]/46,XY[18],同时对从未培养的羊膜细胞中提取的DNA进行aCGH分析，发现arr9p24.3q34.3×2.1（log2比率=0.1）与9三体的10-15％镶嵌性相容。对未培养的羊膜细胞的相间荧光原位杂交（FISH）分析显示，三体性9具有9％（9/100细胞）的镶嵌性。产前超声检查发现IUGR。妊娠持续到妊娠38周，接生了一个2375克表型正常的男婴。脐带的核型,脐带血和胎盘为46，XY（40/40细胞），47,XY,+9[1]/46,XY[39]和47,XY,+9[12]/46,XY[28],分别。对胎盘的QF-PCR测定显示母体来源的三体9。当在两个月的年龄进行随访时，新生儿发育正常。外周血核型为46,XY(40/40细胞),通过间期FISH分析，9三体的颊粘膜细胞具有7.5％（8/106个细胞）的镶嵌性。
结论：羊膜穿刺术中低水平镶嵌三体9可能与良好的胎儿结局以及培养的羊膜细胞和未培养的羊膜细胞之间的细胞遗传学差异有关。
方法：37岁，由于母亲年龄高，初产妇在妊娠17周时接受了羊膜穿刺术。这种妊娠是通过体外受精和胚胎移植（IVF-ET）设想的。羊膜穿刺术显示核型为47，XY，+9[11]/46,XY[32],并对从未培养的羊膜细胞中提取的DNA进行同步阵列比较基因组杂交（aCGH）分析（X，Y)×1,(1-22)×2无基因组失衡。产前超声和亲本核型正常。在妊娠22周时重复羊膜穿刺术显示核型为47，XY，+9[5]/46,XY[19],同时对从未培养的羊膜细胞中提取的DNA进行aCGH分析，发现arr9p24.3q34.3×2.1（log2比率=0.1）与9三体的10-15％镶嵌性相容。定量荧光聚合酶链反应(QF-PCR)测定排除单亲二体(UPD)9.妊娠29周时的第三次羊膜穿刺术显示核型为47，XY，+9[5]/46,XY[18],同时对从未培养的羊膜细胞中提取的DNA进行aCGH分析，发现arr9p24.3q34.3×2.1（log2比率=0.1）与9三体的10-15％镶嵌性相容。对未培养的羊膜细胞的相间荧光原位杂交（FISH）分析显示，三体性9具有9％（9/100细胞）的镶嵌性。产前超声检查发现IUGR。妊娠持续到妊娠38周，接生了一个2375克表型正常的男婴。脐带的核型,脐带血和胎盘为46，XY（40/40细胞），47,XY,+9[1]/46,XY[39]和47,XY,+9[12]/46,XY[28],分别。对胎盘的QF-PCR测定显示母体来源的三体9。当在两个月的年龄进行随访时，新生儿发育正常。外周血核型为46,XY(40/40细胞),通过间期FISH分析，9三体的颊粘膜细胞具有7.5％（8/106个细胞）的镶嵌性。
结论：羊膜穿刺术中低水平镶嵌三体9可能与良好的胎儿结局以及培养的羊膜细胞和未培养的羊膜细胞之间的细胞遗传学差异有关。
