Abstract：
OBJECTIVE: We present low-level mosaic trisomy at amniocentesis in a pregnancy associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the trisomy 7 cell line and a favorable fetal outcome.
METHODS: A 40-year-old, primigravid woman underwent amniocentesis at 16 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY in cultured amniocytes. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr (7) × 2-3, (X,Y) × 1, consistent with 24% mosaicism for trisomy 7. Polymorphic DNA marker analysis on the DNA extracted from the uncultured amniocytes and parental bloods excluded uniparental disomy (UPD) 7. Prenatal ultrasound findings were normal. She was referred for genetic counseling at 19 weeks of gestation. No repeat amniocentesis was suggested, and continuing the pregnancy was advised. At 22 weeks of gestation, the result of soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) = 6.1 (normal < 38). She did not have preeclampsia. At 39 weeks of gestation, a 3346-g male baby was delivered without any phenotypic abnormality. aCGH analysis on the DNA extracted from cord blood and placenta revealed the result of arr (1-22) × 2, (X,Y) × 1 with no genomic imbalance in all tissues. When follow-up at age three months, the baby was normal in development and phenotype. The peripheral blood had a karyotype of 46,XY, and interphase fluorescence in situ hybridization (FISH) analysis using the bacterial artificial chromosome (BAC) probes of chromosome 7 showed disomy 7 cells in all 102/102 cells.
CONCLUSIONS: Low-level mosaic trisomy 7 at amniocentesis can be associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the trisomy 7 cell line and a favorable fetal outcome.
METHODS: A 40-year-old, primigravid woman underwent amniocentesis at 16 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY in cultured amniocytes. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr (7) × 2-3, (X,Y) × 1, consistent with 24% mosaicism for trisomy 7. Polymorphic DNA marker analysis on the DNA extracted from the uncultured amniocytes and parental bloods excluded uniparental disomy (UPD) 7. Prenatal ultrasound findings were normal. She was referred for genetic counseling at 19 weeks of gestation. No repeat amniocentesis was suggested, and continuing the pregnancy was advised. At 22 weeks of gestation, the result of soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) = 6.1 (normal < 38). She did not have preeclampsia. At 39 weeks of gestation, a 3346-g male baby was delivered without any phenotypic abnormality. aCGH analysis on the DNA extracted from cord blood and placenta revealed the result of arr (1-22) × 2, (X,Y) × 1 with no genomic imbalance in all tissues. When follow-up at age three months, the baby was normal in development and phenotype. The peripheral blood had a karyotype of 46,XY, and interphase fluorescence in situ hybridization (FISH) analysis using the bacterial artificial chromosome (BAC) probes of chromosome 7 showed disomy 7 cells in all 102/102 cells.
CONCLUSIONS: Low-level mosaic trisomy 7 at amniocentesis can be associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the trisomy 7 cell line and a favorable fetal outcome.
摘要：
目的：我们在妊娠羊膜穿刺术中呈现低水平镶嵌三体性，这与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。三体7细胞系的围产期进行性减少和有利的胎儿结局。
方法：40岁，由于母亲年龄高，初产妇在妊娠16周时接受了羊膜穿刺术。羊膜穿刺术显示培养的羊膜细胞的核型为46，XY。对从未培养的羊膜细胞中提取的DNA进行的同时阵列比较基因组杂交（aCGH）分析显示了arr（7）×2-3，（X，Y)×1，与三体性7的24%镶嵌性一致。对从未培养的羊水细胞和亲本血液中提取的DNA进行多态性DNA标记分析，排除了单亲二体（UPD）7。产前超声检查结果正常。她在妊娠19周时被转介接受遗传咨询。没有建议重复羊膜穿刺术，建议继续怀孕。妊娠22周时,可溶性fms样酪氨酸激酶-1(sFlt-1)/胎盘生长因子(PlGF)=6.1(正常<38)。她没有先兆子痫。妊娠39周时，一名3346g男婴分娩时没有出现任何表型异常.从脐带血和胎盘提取的DNA的CGH分析显示了ARR（1-22）×2，（X，Y）×1，所有组织均无基因组失衡。在三个月的年龄进行随访时，婴儿的发育和表型正常。外周血核型为46,XY,和使用7号染色体的细菌人工染色体（BAC）探针的相间荧光原位杂交（FISH）分析显示，在所有102/102个细胞中都有二体性7个细胞。
结论：羊膜穿刺术中低水平镶嵌三体7可能与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，三体7细胞系的围产期进行性减少和有利的胎儿结局。
方法：40岁，由于母亲年龄高，初产妇在妊娠16周时接受了羊膜穿刺术。羊膜穿刺术显示培养的羊膜细胞的核型为46，XY。对从未培养的羊膜细胞中提取的DNA进行的同时阵列比较基因组杂交（aCGH）分析显示了arr（7）×2-3，（X，Y)×1，与三体性7的24%镶嵌性一致。对从未培养的羊水细胞和亲本血液中提取的DNA进行多态性DNA标记分析，排除了单亲二体（UPD）7。产前超声检查结果正常。她在妊娠19周时被转介接受遗传咨询。没有建议重复羊膜穿刺术，建议继续怀孕。妊娠22周时,可溶性fms样酪氨酸激酶-1(sFlt-1)/胎盘生长因子(PlGF)=6.1(正常<38)。她没有先兆子痫。妊娠39周时，一名3346g男婴分娩时没有出现任何表型异常.从脐带血和胎盘提取的DNA的CGH分析显示了ARR（1-22）×2，（X，Y）×1，所有组织均无基因组失衡。在三个月的年龄进行随访时，婴儿的发育和表型正常。外周血核型为46,XY,和使用7号染色体的细菌人工染色体（BAC）探针的相间荧光原位杂交（FISH）分析显示，在所有102/102个细胞中都有二体性7个细胞。
结论：羊膜穿刺术中低水平镶嵌三体7可能与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，三体7细胞系的围产期进行性减少和有利的胎儿结局。
