Cytogenetic discrepancy between uncultured amniocytes and cultured amniocytes in mosaic trisomy 15 at amniocentesis in a pregnancy with a favorable outcome.

We present prenatal diagnosis of mosaic trisomy 15 in a pregnancy with a favorable outcome. A 33-year-old, primigravid woman underwent amniocentesis at 19 weeks of gestation because non-invasive prenatal testing (NIPT) revealed gene dosage increase at chromosome 15. Cytogenetic analysis revealed a karyotype of 47,XX,+15[10]/46,XX[13]. Using uncultured amniocytes, array comparative genomic hybridization (aCGH) revealed arr [GRCh37] (X) × 2, (15) × 3 [0.75], multiplex ligation-dependent probe amplification (MLPA) analysis showed rsa [GRCh36] 15q11q13 (21,362,818-27,196,819) × 3 [0.76] and methylation-specific (MS)-MLPA analysis showed a methylation index = 0.41 with paternal gene dosage increase at 15q11-q13. Repeat amniocentesis at 25 weeks of gestation revealed a karyotype of 47,XX,+15[6]/46,XX[14]. Using uncultured amniocytes, quantitative fluorescent polymerase chain reaction (QF-PCR) assays excluded uniparental disomy (UPD) 15 and determined a paternal origin of the extra chromosome 15, aCGH analysis showed 75%-80% mosaicism for trisomy 15, and interphase fluorescence in situ hybridization (FISH) showed 45.5% (46/101 cells) mosaicism for trisomy 15. Repeat amniocentesis at 28 weeks of gestation revealed a karyotype of 47,XX,+15[2]/46,XX[23]. Using uncultured amniocytes, aCGH showed 75-80% mosaicism for trisomy 15, and FISH showed 70.6% (72/102 cells) mosaicism for trisomy 15. Using cultured amniocytes, QF-PCR assays excluded UPD 15. Cordocentesis at 30 weeks of gestation revealed a karyotype of 47,XX,+15[2]/46,XX[138]. Using cord blood, aCGH revealed 9% gene dosage increase at chromosome 15, and MS-MLPA analysis excluded UPD 15. At 36 weeks of gestation, a 2060-g phenotypically normal baby was delivered. The cord blood had 46, XX (40/40 cells). The placenta had 47,XX,+15 (40/40 cells). QF-PCR analysis on placenta showed a paternal origin of trisomy 15. FISH analysis on buccal mucosal cells at age 20 days showed 20% (20/100 cells) mosaicism for trisomy 15. Cytogenetic discrepancy may occur between uncultured and cultured amniocytes in mosaic trisomy 15 at amniocentesis. Cultured amniocytes may present progressive decrease in the levels of mosaicism for trisomy 15 as the fetus grows. Mosaic trisomy 15 at amniocentesis without UPD 15 can be associated with a favorable outcome.

Chen CP ，Ko TM ，Chen TC ，Chern SR ，Wu PS ，Chen SW ，Wu FT ，Chen WL ，Chen YY ，Wang W ... -  《-》

Cytogenetic discrepancy between uncultured amniocytes and cultured amniocytes in mosaic trisomy 18 at amniocentesis in a pregnancy with a favorable fetal outcome and maternal uniparental disomy 18.

We present prenatal diagnosis of mosaic trisomy 18 in a pregnancy with a favorable fetal outcome and maternal uniparental disomy 18. A 38-year-old, primigravid woman underwent the first amniocentesis at 16 weeks of gestation because advanced maternal age. Amniocentesis revealed a karyotype of 46,XX [22/22] in cultured amniocytes, and 36% mosaicism for trisomy 18 and a maternally inherited Xp22.31 microdeletion by array comparative genomic hybridization (aCGH) in uncultured amniocytes. The second amniocentesis at 18 weeks of gestation revealed 47,XX,+18 [14]/46,XX [36] in cultured amniocytes and 36% mosaicism for trisomy 18 by multiplex ligation-dependent probe amplification (MLPA) P095 in cultured amniocytes. Prenatal ultrasound was normal. The parents were phenotypically normal. The third amniocentesis at 23 weeks of gestation revealed 47,XX,+18 [3]/46,XX [17] in cultured amniocytes, and in uncultured amniocytes, aCGH revealed 45%-50% mosaicism for trisomy 18, interphase fluorescence in situ hybridization (FISH) revealed 36% (36/100 cells) mosaicism for trisomy 18, and quantitative fluorescent polymerase chain reaction (QF-PCR) showed mosaic maternal uniparental heterodisomy for chromosome 18 and mosaic trisomy 18 of maternal origin. The fourth amniocentesis at 32 weeks of gestation revealed a karyotype of 46,XX [20/20] in cultured amniocytes, and in uncultured amniocytes, aCGH revealed 50%-60% mosaicism for trisomy 18, FISH revealed 21.8% (22/101 cells) mosaicism for trisomy 18, and non-invasive prenatal testing (NIPT) showed chromosome 18 gene dosage increase in the maternal blood. At 34 weeks of gestation, a 1480-g phenotypically normal baby was delivered. The cord blood had 47,XX,+18 [10]/46,XX [30]. The umbilical cord had 47,XX,+18 [4]/46,XX [36]. The placenta had 47,XX,+18 [40/40], and QF-PCR analysis confirmed trisomy 18 of maternal origin. When follow-up at age four months, the neonate was phenotypically normal, FISH analysis on buccal mucosal cells revealed 2% (2/100 cells) mosaicism for trisomy 18, and the peripheral blood had 47,XX,+18 [18]/46,XX [22]. When follow-up at age eight months, the neonate had normal development, the peripheral blood had 47,XX,+18 [15]/46,XX [25], and the buccal mucosal cells showed maternal uniparental heterodisomy for chromosome 18. Cytogenetic discrepancy may occur between uncultured and cultured amniocytes in mosaic trisomy 18 at amniocentesis. Cultured amniocytes may present progressive decrease in the levels of mosaicism for trisomy 18 as the fetus grows. Mosaic trisomy 18 at amniocentesis can be associated with a favorable outcome.

Chen CP ，Su JW ，Chern SR ，Wu PS ，Chen SW ，Wu FT ，Chen WL ，Lee MS ，Pan CW ，Chen YY ，Wang W ... -  《-》

Cytogenetic discrepancy between uncultured amniocytes and cultured amniocytes in mosaic trisomy 15 at amniocentesis.

We present mosaic trisomy 15 at amniocentesis. A 41-year-old woman underwent amniocentesis at 16 weeks of gestation because of an abnormal non-invasive prenatal testing (NIPT) result suspicious of trisomy 15. Amniocentesis revealed a karyotype of 46,XY. Array comparative genomic hybridization (aCGH) on uncultured amniocytes revealed 26% mosaicism for trisomy 15. She was referred for repeat amniocentesis. aCGH, interphase fluorescence in situ hybridization (FISH), quantitative fluorescent polymerase chain reaction (QF-PCR) assays and/or conventional cytogenetic analysis were applied on various cells and tissues including uncultured amniocytes, cultured amniocytes, cord blood, placenta, parental bloods and/or buccal mucosal cells. Repeat amniocentesis at 21 weeks of gestation revealed a karyotype of 46, XY in cultured amniocytes, and 30% mosaicism for trisomy 15 by aCGH and 32% mosaicism for trisomy 15 by FISH in uncultured amniocytes. Repeat amniocentesis at 29 weeks of gestation revealed a karyotype of 46, XY in cultured amniocytes, and 15% mosaicism for trisomy 15 by aCGH and 7.2% mosaicism for trisomy 15 by FISH in uncultured amniocytes. QF-PCR on cultured amniocytes excluded uniparental disomy (UPD) 15. A phenotypically normal baby was delivered subsequently with a karyotype of 46, XY in cord blood and 2% mosaicism for trisomy 15 by FISH in buccal mucosal cells. The aCGH analysis revealed trisomy 15 in placenta and no genomic imbalance in cord blood. QF-PCR assays determined a maternal origin of trisomy 15 in placenta. Cytogenetic discrepancy may occur between uncultured and cultured amniocytes in mosaic trisomy 15 at amniocentesis. The cells of trisomy 15 cell line in prenatally detected mosaic trisomy 15 may decrease in number as the fetus grows. Whenever NIPT suspects trisomy 15, a confirmatory amniocentesis should include genetic analysis on both uncultured and cultured amniocytes to exclude mosaic trisomy 15 and maternal UPD 15, especially when the cultured amniocytes have a normal karyotype.

Chen CP ，Hsu TY ，Ko TM ，Chern SR ，Wu PS ，Chen SW ，Wu FT ，Chen YY ，Lee CC ，Pan CW ，Wang W ... -  《-》

Low-level mosaic trisomy 15 at amniocentesis without uniparental disomy 15 in a pregnancy associated with cytogenetic discrepancy between uncultured amniocytes and cultured amniocytes, a favorable fetal outcome and perinatal decrease of the aneuploid cell

We present low-level mosaic trisomy 15 without uniparental disomy (UPD) 15 in a pregnancy associated with cytogenetic discrepancy between uncultured amniocytes and cultured amniocytes, a favorable fetal outcome and perinatal decrease of the aneuploid cell line. A 40-year-old, gravida 2, para 0, woman underwent amniocentesis at 16 weeks of gestation because advanced maternal age. This pregnancy was conceived by in vitro fertilization and embryo transfer. Amniocentesis revealed a karyotype of 47,XX,+15 [7]/46,XX [43]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed arr (15) × 2-3 (X) × 2 with 14% mosaicism for trisomy 15, and ME028 multiplex ligation-dependent probe amplification (MLPA) methylation test excluded UPD 15. Prenatal ultrasound and parental karyotypes were normal. She was referred for genetic counseling, and repeat amniocentesis performed at 28 weeks of gestation revealed 46, XX (20/20 colonies) in cultured amniocytes, and in uncultured amniocytes, interphase fluorescence in situ hybridization (FISH) showed 13.7% (16/117 cells) mosaicism for trisomy 15, aCGH analysis revealed arr [GRCh(hg19)] 15q11.22q26.3 (22, 765, 628-102,256,748) × 2.4 with a log2 ratio = 0.26, consistent with 40% mosaicism for trisomy 15, and quantitative fluorescent polymerase chain reaction (QF-PCR) assays excluded UPD 15. The woman was encouraged to continue the pregnancy. At 37 weeks of gestation, a 2400-g phenotypically normal female baby was delivered without any abnormality. The cord blood had 46, XX (40/40 cells). QF-PCR assays determined maternal origin of trisomy 15 in the placenta. When follow-up at age 5 months, the neonate was normal in physical and psychomotor development. FISH analysis on 102 buccal mucosal cells detected 2 cells (2%, 2/102 cells) with trisomy 15 signals, compared with 1% in normal control. Low-level mosaic trisomy 15 at amniocentesis without UPD 15 can be a transient and benign condition, and can be associated with a favorable fetal outcome and perinatal decrease of the aneuploid cell line.

Chen CP ，Chen SW ，Chern SR ，Wu PS ，Wu FT ，Pan YT ，Chen YY ，Wang W ... -  《-》

Low-level mosaic trisomy 2 at amniocentesis in a pregnancy associated with positive NIPT and CVS results for trisomy 2, maternal uniparental disomy 2, perinatal progressive decrease of the aneuploid cell line, cytogenetic discrepancy between cultured amni

We present low-level mosaic trisomy 2 at amniocentesis in a pregnancy associated with positive non-invasive prenatal testing (NIPT) and chorionic villus sampling (CVS) results for trisomy 2, maternal uniparental disomy (UPD) 2, perinatal progressive decrease of the aneuploid cell line, cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, intrauterine growth restriction (IUGR) and a favorable fetal outcome. A 35-year-old, primigravid woman underwent amniocentesis at 16 weeks of gestation because both NIPT at 9 weeks of gestation and CVS at 11 weeks of gestation revealed trisomy 2. This pregnancy was conceived by in vitro fertilization (IVF) and embryo transfer (ET). Amniocentesis revealed a karyotype of 47,XY,+2[11]/46,XY[19]. Prenatal ultrasound findings were normal. She was referred to the hospital for genetic counseling at 20 weeks of gestation, and repeat amniocentesis performed at 24 weeks of gestation revealed a karyotype of 46,XY (22/22 colonies). The parental karyotypes were normal. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from uncultured amniocytes and parental bloods revealed maternal uniparental heterodisomy of chromosome 2. Simultaneous molecular cytogenetic analysis on uncultured amniocytes showed the results of arr 2p25.3q37.3 × 2.4 with a log2 ratio = 0.26, consistent with 40% mosaicism for trisomy 2 by array comparative genomic hybridization (aCGH), and 28% (28/100 cells) mosaicism for trisomy 2 by interphase fluorescence in situ hybridization (FISH). Despite IUGR on fetal ultrasound, the woman was advised to continue the pregnancy, and a 2252-g phenotypically normal male baby was delivered at 38 weeks of gestation. The karyotypes of cord blood, umbilical cord and placenta were 46,XY (40/40 colonies), 46,XY (40/40 colonies) and 47,XY,+2[9]/46,XY[31], respectively. QF-PCR analysis on cord blood, umbilical cord and placenta confirmed uniparental heterodisomy of chromosome 2 in the cord blood and umbilical cord, and maternal origin of trisomy 2 in the placenta. FISH analysis on buccal mucosal cells at age 1.5 months revealed 8.7% (9/104 cells) mosaicism for trisomy 2. When follow-up at age four months, the neonate manifested a normal phenotype except intermittent hypoventilation. Molecular analysis of the PHOX2B gene revealed a normal result. When follow-up at age one year, he manifested normal development. Mosaic trisomy 2 at prenatal diagnosis should alert the possibility of UPD 2 and include a UPD 2 testing. Low-level mosaic trisomy 2 at amniocentesis can be associated with perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.

Chen CP ，Wu FT ，Chern SR ，Wu PS ，Pan YT ，Lee CC ，Pan CW ，Wang W ... -  《-》