Low-level mosaic trisomy 21 at amniocentesis and cordocentesis in a pregnancy associated with a favorable fetal outcome and perinatal progressive decrease of the trisomy 21 cell line.

OBJECTIVE: We present low-level mosaic trisomy 21 at amniocentesis and cordocentesis in a pregnancy associated with a favorable fetal outcome and perinatal progressive decrease of the trisomy 21 cell line. CASE REPORT: A 36-year-old, primigravid woman underwent amniocentesis at 16 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,+21 [3]/46,XY [17] (15% mosaicism) and simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr (21) × 2∼3 (X,Y) × 1, consistent with 24.5% mosaicism for trisomy 21. Cordocentesis performed at 21 weeks of gestation revealed a karyotype of 47,XY,+21 [3]/46,XY [37] (6% mosaicism). She was referred for genetic counseling at 31 weeks of gestation, and continuing the pregnancy was advised. The parental karyotypes and prenatal ultrasound were normal. At 37 weeks of gestation, a phenotypically normal baby was delivered with a body weight of 2900-g. The karyotypes of cord blood, umbilical cord and placenta were 47,XY,+21 [1]/46,XY [39] (2.5% mosaicism), 47,XY,+21 [10]/46,XY [30] (25% mosaicism) and 47,XY,+21 [22]/46,XY [18] (55% mosaicism), respectively. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from umbilical cord and parental bloods excluded uniparental disomy (UPD) 21 and revealed a maternal origin of the extra chromosome 21. When follow-up at the age of 2 months, the neonate was normal in phenotype and development. The peripheral blood had a karyotype of 47,XY,+21 [1]/46,XY [39] (2.5% mosaicism), and interphase fluorescence in situ hybridization (FISH) analysis on uncultured buccal mucosal cells revealed 4.7% (5/105 cells) mosaicism for trisomy 21, compared with 0% (5/100 cells) in the normal control. CONCLUSION: Low-level mosaic trisomy 21 at amniocentesis and cordocentesis can be associated with favorable fetal outcome and perinatal progressive decrease of the trisomy 21 cell line.

First-trimester application of expanded non-invasive prenatal testing in the genetic investigation of fetal 1p36 deletion syndrome associated with a familial unbalanced reciprocal translocation of 46,XX,der(1)t(1;2) (p36.2;q37.3)dmat.

OBJECTIVE: We present first-trimester application of expanded non-invasive prenatal testing (NIPT) in the genetic investigation of fetal 1p36 deletion syndrome associated with a familial unbalanced reciprocal translocation of 46,XX,der(1)t(1;2) (p36.2;q37.3)dmat. CASE REPORT: A 37-year-old, gravida 2, para 0, woman underwent expanded NIPT at 13 weeks of gestation because of advanced maternal age and the fear of complications of invasive procedures of prenatal diagnosis. She had experienced one spontaneous abortion. The pregnancy was conceived by in vitro fertilization and embryo transfer (IVF-ET) because of tubal occlusion. NIPT was positive for 1p36 deletion. At 17 weeks of gestation, she underwent amniocentesis but intrauterine fetal death occurred after amniocentesis and the pregnancy was terminated. Amniocentesis revealed a derivative chromosome 1 with an aberrant short arm terminal segment of chromosome 1. Subsequent cytogenetic analysis of parental bloods showed a karyotype of 46,XY in the father and a karyotype of 46,XX,t(1;2) (p36.2;q37.3) in the mother. The karyotype of amniocytes was 46,XX,der(1)t(1;2) (p36.2;q37.3)dmat, consistent with partial monosomy 1p (1p36.2→pter) and partial trisomy 2q (2q37.3→qter). Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from cultured amniocytes revealed the result of arr 1p36.33p36.22 (852,863-11,303,452) × 1.0 and arr 2q37.3 (242,785,405-243,068,396) × 3.0 [GRCh 37] with a 10.451-Mb deletion of 1p36.33-p36.22 encompassing 116 OMIM genes including RERE and a 283-kb duplication of 2q37.3 encompassing one OMIM gene of PDCD1. CONCLUSION: Expanded NIPT has the advantage of early detection of familial unbalanced reciprocal translocation in the fetus.

Prenatal diagnosis of Jacobsen syndrome associated with a distal 11q deletion and a distal 8q duplication by chromosome microarray analysis in a fetus with a de novo unbalanced translocation of 46,XX,der(11)t(8;11)(q24.13;q23.3) and multiple congenital anomalies on fetal ultrasound.

OBJECTIVE: We present prenatal diagnosis of Jacobsen syndrome associated with a distal 11q deletion and a distal 8q duplication by chromosome microarray analysis (CMA) in a fetus with multiple congenital anomalies on fetal ultrasound. CASE REPORT: A 41-year-old, gravida 2, para 1, woman underwent amniocentesis at 25 weeks of gestation because of intrauterine growth restriction, endocardial cushion defect, clenched hands, arthrogryposis, rocker bottom feet and craniosynostosis on fetal ultrasound. Amniocentesis revealed a karyotype of 46,XX,add(11)(q23.3). Array comparative genomic hybridization (aCGH) analysis of the DNA extracted from the uncultured amniocytes revealed the result of arr 8q24.13q24.3 × 3, 11q23.3q25 × 1. Analysis of FGFR2 revealed no mutation. The karyotype was 46,XX,der(11)t(8;11)(q24.13;q23.3). The parental karyotypes were normal. The pregnancy was subsequently terminated, and a dead malformed fetus was delivered with craniofacial dysmorphism of low-set malformed ears, depressed nasal bridge, hypertelorism, small mouth, clenched hands and rocker bottom feet. Cytogenetic analysis of the placenta revealed a karyotype of 46,XX,der(11)t(8;11)(q24.13;q23.3). aCGH analysis of the DNA extracted from the umbilical cord showed the result of arr 8q24.13q24.3 (126,302,369-146,280,020) × 3.0, arr 11q23.3q25 (120,469,928-134,868,407) × 1.0 [GRCh37] with a 19.978-Mb duplication of 8q24.13-q24.3 and a 14.398-Mb deletion of 11q23.3-q25 encompassing the genes of BSX, ETS1, FLI1 and ARHGAP32. CONCLUSION: CMA is useful for detection of de novo chromosomal rearrangement in the fetus with multiple congenital anomalies on fetal ultrasound.

Detection of chromosome 5q interstitial deletion of 5q14.3-q31.1 by chromosome microarray analysis in a second-trimester fetus with multiple congenital anomalies and a literature review of chromosome 5q interstitial deletion syndrome.

OBJECTIVE: We present application of chromosome microarray analysis (CMA) in the detection of chromosome 5q interstitial deletion of 5q14.3-q31.1 in a second-trimester fetus with multiple congenital anomalies on fetal ultrasound. CASE REPORT: A 30-year-old, gravida 2, para 1, woman was found to have multiple anomalies in the fetus at 14 weeks of gestation by prenatal ultrasound screening. The fetal anomalies included echogenic bowel, a left neck cyst, hypoplastic left heart, single umbilical artery and bilateral clubfeet. The pregnancy was subsequently terminated, and a 64-g malformed fetus was delivered. CMA by array comparative genomic hybridization (aCGH) analysis on the DNA extracted from umbilical cord revealed the result of arr 5q14.3q31.1 (83,557,042-130,841,093) × 1.0 [GRCh37] with a 47.3-Mb 5q14.3-q31.1 deletion encompassing 95 OMIM genes including NR2F1, MEF2C, APC, KCNN2 and FBN2. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from parental bloods and umbilical cord using the informative markers of D5S2496 (5q21.3) and D5S818 (5q23.2) showed that the fetus inherited only one maternal allele, indicating a paternal origin of the interstitial 5q deletion in the fetus. CONCLUSION: CMA is useful for genetic investigation of unknown congenital anomalies detected by fetal ultrasound.

Prenatal diagnosis of a 14-Mb 11p11.2-p13 deletion by chromosome microarray analysis in a pregnancy with fetal recombinant chromosome 11 syndrome of rec(11)del(11)(p11.2p13)ins(11)(q21p11.2p13) and maternal intrachromosomal insertion of ins(11)(q21p11.2p13).

OBJECTIVE: We present prenatal diagnosis of a 14-Mb 11p11.2-p13 deletion by chromosome microarray analysis (CMA) in a pregnancy with fetal recombinant chromosome 11 syndrome of rec(11)del(11) (p11.2p13)ins(11) (q21p11.2p13) and maternal intrachromosomal insertion of ins(11) (q21p11.2p13). CASE REPORT: A 25-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of a family history of psychiatric disorders in her two brothers and one maternal uncle. Array comparative genomic hybridization (aCGH) analysis of amniocentesis revealed a 14-Mb 11p13p11.2 deletion. The pregnancy was terminated at 19 weeks of gestation, and a 252-g fetus was delivered. Cytogenetic analysis of the parental bloods and cord blood revealed a karyotype of 46,XX,ins(11) (q21p11.2p13) in the mother, 46,XY in the father and 46,XY,rec(11)del(11) (p11.2p13)ins(11) (q21p11.2p13) in the fetus. aCGH analysis on the DNA extracted from cord blood revealed the result of arr 11p13q11.2 (32,697,424-46,712,173) × 1.0 [GRCh37] with a 14-Mb deletion of 11p13-p11.2 encompassing 54 OMIM genes including PHF21A, ALX4, EXT2 and SLC1A2. Polymorphic DNA marker analysis showed a maternal origin of the 11p deletion. The present case had an 11p13-p11.2 deletion encompassing 11p12-p11.3 which is associated with Potocki-Shaffer syndrome (PSS) or chromosome 11p11.2 deletion syndrome. CONCLUSION: CMA is useful for prenatal detection of fetal genomic imbalance in case of familial intrachromosomal insertion.

Low-level mosaic trisomy 21 due to mosaic unbalanced Robertsonian translocation of 46,XX,+21,der(21;21) (q10;q10)/46,XX at amniocentesis in a pregnancy associated with a favorable fetal outcome, cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, cytogenetic discrepancy among various tissues and perinatal progressive decrease of the trisomy 21 cell line.

OBJECTIVE: We present prenatal diagnosis of mosaic trisomy 21 at amniocentesis associated with unbalanced Robertsonian translocation in the fetus and a favorable fetal outcome. CASE REPORT: A 41-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Her husband was 41 years old. Amniocentesis revealed a karyotype of 46,XX,+21,der(21;21) (q10;q10)[8]/46,XX[18], consistent with 30.8% (8/26 colonies) mosaicism for trisomy 21. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr (1-22,X) × 2 with no genomic imbalance. Repeat amniocentesis at 21 weeks of gestation revealed a karyotype of 46,XX,+21,der(21;21) (q10;q10)[2]/46,XX[25], consistent with 7.4% (2/27 colonies) mosaicism for trisomy 21. Cord blood sampling revealed the result of 46,XX and rsa X(P095) × 2, 13,18,21(P095) × 2. Prenatal ultrasound findings were normal. At 23 weeks of gestation, she underwent cord blood sampling which revealed a karyotype of 46,XX. At 26 weeks of gestation, she was referred for genetic counseling. No repeat amniocentesis and continuing the pregnancy were advised. The mother had a karyotype of 46,XX, and the father had a karyotype of 46,XY. At 38 weeks of gestation, a 3476-g, phenotypically normal baby was delivered. The cord blood had a karyotype of 46,XX,+21,der(21;21) (q10;q10)[1]/46,XX[39] (2.5% mosaicism). The placenta had a karyotype of 46,XX,+21,der(21;21) (q10;q10) (40/40 cells). When follow-up at age two months, the neonate was normal in phenotype and development. The peripheral blood had a karyotype of 46,XX (40/40 cells), and aCGH analysis on buccal mucosal cells resulted no genomic imbalance. CONCLUSION: Low-level mosaic trisomy 21 at amniocentesis due to mosaic unbalanced Robertsonian translocation with a normal cell line can be associated with a favorable fetal outcome, cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, cytogenetic discrepancy among various tissues and perinatal progressive decrease of the trisomy 21 cell line.

Low-level mosaic trisomy 14 at amniocentesis in a pregnancy associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, positive non-invasive prenatal testing for trisomy 14, perinatal progressive decrease of the trisomy 14 cell line and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy 14 at amniocentesis. CASE REPORT: A 37-year-old, gravida 2, para 1, woman underwent amniocentesis at 18 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,XX,+14 [4]/46,XX [27], consistent with 12.9% mosaicism for trisomy 14. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr (1-22, X) × 2 with no genomic imbalance. Prenatal ultrasound findings were unremarkable. She was referred for genetic counseling at 21 weeks of gestation and was offered expanded non-invasive prenatal testing (NIPT) which was positive for trisomy 14. At 24 weeks of gestation, she underwent repeat amniocentesis which revealed a karyotype of 47,XX,+14 [2]/46,XX [26], consistent with 7% mosaicism for trisomy 14. The parental karyotypes were normal. Simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes revealed no genomic imbalance. Polymorphic marker analysis excluded uniparental disomy (UPD) 14. Interphase fluorescence in situ hybridization (FISH) analysis on 104 uncultured amniocytes detected no trisomy 14 cell. At 35 weeks of gestation, a 2315-g phenotypically normal baby was delivered. The umbilical cord and placenta had the karyotype of 46, XX (40/40 cells). aCGH analysis on the DNA extracted from peripheral blood and buccal mucosal cells at the age of three months revealed no genomic imbalance. The neonate was normal in phenotype and development during postnatal follow-ups. CONCLUSIONS: Low-level mosaic trisomy 14 at amniocentesis can be associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the trisomy 14 cell line and a favorable fetal outcome.

Mosaic distal 13q duplication due to mosaic unbalanced translocation of 46,XY,der(14)t(13;14)(q32.2;p13)/46,XY at amniocentesis in a pregnancy associated with a favorable fetal outcome, perinatal progressive decrease of the aneuploid cell line and cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes.

OBJECTIVE: We present mosaic distal 13q duplication due to mosaic unbalanced translocation 46,XY,der(14)t(13;14)(q32.2;p13)/46,XY at amniocentesis in a pregnancy associated with a favorable fetal outcome. CASE REPORT: A 37-year-old, gravida 2, para 0, woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY, add(14) (p13)[17]/46,XY[13] (56.6% mosaicism). Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from cultured amniocytes revealed arr 13q32.2q34 × 2∼3, consistent with 45% mosaicism for distal 13q duplication. Repeat amniocentesis at 24 weeks of gestation revealed a karyotype of 46,XY,der(14)t(13;14)(q32.2;p13)[14]/46,XY[16] (46.6% mosaicism). The parental karyotypes were normal. aCGH analysis on the DNA extracted from uncultured amniocytes revealed arr 13q32.2q34 × 2.38, consistent with 30-40% mosaicism for distal 13q duplication. Interphase fluorescence in situ hybridization (FISH) analysis on uncultured amniocytes detected 22.8% (23/101 cells) mosaicism for distal 13q duplication. Prenatal ultrasound findings were unremarkable. At 39 weeks of gestation, a 3616-g phenotypically normal baby was delivered. The karyotypes of cord blood, umbilical cord and placenta were 46,XY,der(14)t(13;14)(q32.2;p13)[20]/46,XY[20] (50% mosaicism), 46,XY,der(14)t(13;14)(q32.2;p13)[14]/46,XY[26] (35% mosaicism) and 46,XY (40/40 cells) (0% mosaicism), respectively. When follow-ups at the age of 4½ months and the age of one year, the peripheral blood had the karyotype of 46,XY,der(14)t(13;14)(q32.2;p13)[18]/46,XY[22] (45% mosaicism). Interphase FISH analysis on buccal mucosal cells at the age of 4½ months revealed 2.7% (3/110 cells) mosaicism for distal 13q duplication, compared with 1% (1/100 cells) in the normal control. The neonate was normal in phenotype and development. CONCLUSIONS: Mosaic unbalanced translocation at amniocentesis can be associated with a favorable fetal outcome, perinatal progressive decrease of the aneuploid cell line and cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes.

Genetic counseling of mosaicism for a duplication due to partial trisomy in a cell line with 46 chromosomes associated with a normal cell line at amniocentesis.

Genetic counseling of mosaicism for a duplication due to partial trisomy in a cell line with 46 chromosomes associated with a normal cell line at amniocentesis remains difficult because mosaic duplication due to partial trisomy has been reported to be associated with either normal or abnormal phenotype in prenatal diagnosis. This article makes a comprehensive review of the reported cases of mosaicism for a duplication due to partial trisomy in a cell line with 46 chromosomes associated with a normal cell line at amniocentesis and various counseling issues such as culture artefact, cytogenetic discrepancy between cultured and uncultured amniocytes and among various tissues, perinatal progressive decrease of the abnormal cell line and a possible favorable fetal outcome. The information provided is useful for obstetricians and genetic counselors during genetic counseling of the parents who wish to keep the babies under such a circumstance.

Genetic counseling of mosaic and non-mosaic tetrasomy 9p at prenatal diagnosis.

Genetic counseling of mosaic and non-mosaic tetrasomy 9p remains difficult because of the possible associated congenital abnormalities, cytogenetic discrepancy in various tissues, true-positive and false-positive diagnosis in non-invasive prenatal testing (NIPT), uniparental disomy (UPD) 9, tissue-limited mosaicism, perinatal progressive decrease of the aneuploid cell line, phenotypic normal carriers and possible favorable fetal outcome in the cases with mosaic tetrasomy 9p at amniocentesis. This article presents a comprehensive review of various counseling issues concerning mosaic and non-mosaic tetrasomy 9p at prenatal diagnosis, and the information provided is very useful for genetic counseling under such circumstances.

Genetic counseling of mosaicism for balanced or unbalanced translocation with a normal cell line at amniocentesis.

Genetic counseling of mosaicism for balanced translocation with a normal cell line at amniocentesis is not difficult because most of the reported cases have normal phenotypes. However, genetic counseling of mosaicism for unbalanced translocation with a normal cell line at amniocentesis remains difficult because cases with mosaic unbalanced translocation with a normal cell line at prenatal diagnosis have been reported to be associated with either normal or abnormal phenotype. This article makes a comprehensive review of the reported cases of de novo or familial mosaic unbalanced translocation with a normal cell line and various counseling issues such as meiotic event, post-zygotic mitotic event, culture artefact, chimerism, uniparental disomy (UPD), jumping translocation, cytogenetic discrepancy between cultured and uncultured amniocytes and among various tissues, perinatal progressive decrease of the unbalanced translocation cell line and a possible favorable fetal outcome. The information provided is useful for obstetricians and genetic counselors during genetic counseling of the parents who wish to keep the babies under such a circumstance.