Incidental detection of familial 8p23.2 microduplication encompassing CSMD1 associated with mosaic 46,XY,t(7;8)(q31.2;p23.1)/46,XY at amniocentesis in a pregnancy with no apparent phenotypic abnormality and a favorable outcome.

OBJECTIVE: We present incidental detection of familial 8p23.2 microduplication encompassing CSMD1 associated with mosaic 46,XY,t(7;8)(q31.2;p23.1)/46,XY at amniocentesis in a pregnancy with no apparent phenotypic abnormality and a favorable outcome. CASE REPORT: A 38-year-old, gravida 2, para 1, phenotypically normal woman underwent amniocentesis at 19 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY,t(7;8)(q31.2;p23.1)[2]/46,XY[20]. The parental karyotypes were normal. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from cultured amniocytes and parental bloods revealed the result of a 2.178-Mb 8p23.2 microduplication encompassing CSMD1, or arr 8p23.2 (3,070,237-5,248,586) × 3.0 [GRCh37 (hg19)] in the fetus and the mother. The father did not have such a microduplicaiton. Prenatal ultrasound findings were unremarkable. At 38 weeks of gestation, a 2880-g phenotypically normal male baby was delivered. All the cord blood, umbilical cord and placenta had the karyotype of 46.XY. When follow-up at age six months, the neonate was normal in phenotype and development. CONCLUSION: Mosaicism for a balanced reciprocal translocation with a euploid cell line can be a transient and benign condition. Familial 8p23.2 microduplication encompassing CSMD1 can be associated with a favorable outcome.

Prenatal diagnosis and perinatal findings of 17q12 microdeletion encompassing HNF1B in a fetus with bilateral hyperechogenic kidneys on fetal ultrasound and mild renal abnormality after birth, and a review of the literature of prenatal diagnosis of 17q12 microdeletion.

OBJECTIVE: We present prenatal diagnosis and perinatal findings of 17q12 microdeletion encompassing HNF1B in a fetus with bilateral hyperechogenic kidneys on fetal ultrasound and mild renal abnormality after birth, and a review of the literature. CASE REPORT: A 36-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes showed a de novo 1.38-Mb 17q12 microdeletion encompassing LHX1 and HNF1B. The parents did not have such a microdeletion. Prenatal ultrasound showed bilateral hyperechogenic kidneys with normal corticomedullary (CM) differentiation. The parents elected to continue the pregnancy, and a grossly normal 3180-g male baby was delivered at 39 weeks of gestation. aCGH analysis on the cord blood DNA revealed arr [GRCh37 (hg19)] 17q12 (34,856,055-36,248,918) × 1.0 with a 1.393-Mb microdeletion encompassing the genes of MYO19, PIGW, GGNBP2, DHRS11, MRM1, LHX1, AATF, ACACA, TADA2A, DUSP14, SYNRG, DDX52 and HNF1B. When follow-up at age 2 years and 4 months, the renal ultrasound revealed bilateral increased renal echogenicity with normal CM differentiation and small left renal cysts. The blood test revealed BUN = 28 mg/dL (normal: 5-18 mg/dL) and creatinine = 0.5 mg/dL (normal: 0.2-0.4 mg/dL). CONCLUSION: 17q12 microdeletion encompassing LHX1 and HNF1B at prenatal diagnosis may present variable clinical spectrum with bilateral hyperechogenic kidneys on fetal ultrasound and mild renal abnormality after birth. Prenatal diagnosis of fetal hyperechogenic kidneys should raise a suspicion of 17q12 microdeletion syndrome.

The correlation with abnormal fetal outcome and a high level of amniotic fluid alpha-fetoprotein in mid-trimester.

OBJECTIVE: To evaluate the correlation of high levels [>2.0 multiples of median (MoM)] of amniotic fluid alpha-fetoprotein (AFAFP) in midtrimester with abnormal fetal outcome. MATERIALS AND METHODS: We retrospectively studied 6245 pregnant women with singleton pregnancy who had undergone amniocentesis between 15 and 27 weeks' gestation at Mackay Memorial Hospital between January 2014 and June 2020. Fifty-five cases had high AFAFP levels (>2.0 MoM). We investigated the abnormal fetal outcomes. RESULTS: Among the fifty-five cases with high AFAFP levels (>2.0 MoM), thirty (54.5%) had fetal chromosomal abnormalities, major structural abnormalities, and/or adverse obstetric events. Eight cases (14.5%) had chromosomal abnormalities including trisomy 21 (3 cases), trisomy 18 (3 cases), mosaic trisomy 18 (1 cases), and mosaic ring 13 (1 case). Seventeen cases (30.9%) had major structural abnormalities including abdominal wall defect (6 cases) and central nervous system (5 cases), gastrointestinal tract (3 cases), cardiovascular (2 cases), and genitourinary tract (2 cases) abnormalities. Fifteen cases (27%) had adverse obstetric events, including preterm delivery (5 cases), intrauterine fetal demise (4 cases), small for gestational age (4 cases), preeclampsia (4 cases), gestational diabetes mellitus (2 cases), gestational hypertension (1 case), preterm prelabor rupture of membrane (1 case), prolonged labor (1 case), and preterm uterine contraction (1 case). CONCLUSION: A high AFAFP level (>2.0 MoM) in midtrimester can be associated with abnormal fetal outcome, including chromosomal abnormalities, major structural abnormalities, and adverse obstetric events. Women with a prenatal diagnosis of high AFAFP levels (>2.0 MoM) should be alerted of the possibility of abnormal fetal outcomes, and further detailed genetic studies and serial sonographic examinations are recommended.

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

OBJECTIVE: We present low-level mosaic trisomy 21 at amniocentesis in a pregnancy associated with cytogenetic discrepancy in various tissues, perinatal progressive decrease of the trisomy 21 cell line and a favorable fetal outcome. CASE REPORT: A 36-year-old, gravida 2, para 1, woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age, and the result was 47,XY,+21 [8]/46,XY [26]. Prenatal ultrasound findings were unremarkable. She was referred for genetic counseling, and repeat amniocentesis performed at 23 weeks of gestation revealed the result of 47,XY,+21 [3]/46,XY [21]. The parental karyotypes were normal. At repeat amniocentesis, quantitative fluorescent polymerase chain reaction (QF-PCR) analysis using the DNA extracted from uncultured amniocytes and parental bloods excluded uniparental disomy (UPD) 21, array comparative genomic hybridization (aCGH) analysis on uncultured amniocytes revealed the result of arr 21q11.2q22.3 × 2.4, consistent with 40% mosaicism for trisomy 21, and fluorescence in situ hybridization (FISH) analysis on uncultured amniocytes revealed 67% (67/100 cells) mosaicism for trisomy 21. The woman was advised to continue the pregnancy, and a 1370-g male baby was delivered prematurely at 29 weeks of gestation without phenotypic abnormalities. The karyotypes of umbilical cord and placenta were 47,XY,+21 [13]/46,XY [27] and 47,XY,+21 [40], respectively. QF-PCR determined maternal origin of the extra chromosome 21 of trisomy 21 in the placenta. When follow-up at age 8½ months, the neonate was normal in appearance and development. The peripheral blood had a karyotype of 47,XY,+21 [1]/46,XY [39], and FISH analysis on buccal mucosal cells showed 9.7% (11/113 cells) mosaicism for trisomy 21, compared with 2% (2/100 cells) in the normal control. CONCLUSION: Low-level mosaic trisomy 21 at amniocentesis can be associated with cytogenetic discrepancy in various tissues, perinatal progressive decrease of the trisomy 21 cell line and a favorable fetal outcome.

High-level mosaic trisomy 21 at amniocentesis in a pregnancy associated with positive NIPT for trisomy 21, prenatal progressive decrease of the trisomy 21 cell line, acute fatty liver of pregnancy and intrauterine fetal death in late gestation.

OBJECTIVE: We present high-level mosaic trisomy 21 at amniocentesis in a pregnancy associated with positive non-invasive prenatal testing (NIPT) for trisomy 21, prenatal progressive decrease of the trisomy 21 cell line, acute fatty liver of pregnancy and intrauterine fetal death (IUFD) in late gestation. CASE REPORT: A 32-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of positive NIPT for trisomy 21 at 12 weeks of gestation. This pregnancy was conceived by in vitro fertilization. She did not have obesity, diabetes mellitus, hepatic biliary disorders and preeclampsia. Amniocentesis revealed a karyotype of 47,XY,+21[10]/46,XY[11], and array comparative genomic hybridization (aCGH) analysis on uncultured amniocytes revealed the result of arr (21) × 2-3. She was referred for genetic counseling, and repeat amniocentesis performed at 21 weeks of gestation revealed the karyotype of 47,XY,+21[10]/46,XY[28]. The parental karyotypes and fetal ultrasound findings were normal. Simultaneous molecular analysis on uncultured amniocytes showed no uniparental disomy 21, but a maternal origin of trisomy 21 by quantitative fluorescent polymerase chain reaction (QF-PCR) and the result of arr 21q11.2q22.3 × 2.5 by aCGH analysis. At 27 weeks of gestation, she underwent a third amniocentesis, of which conventional cytogenetic analysis revealed the result of 47,XY,+21[5]/46,XY[17] in cultured amniocytes, and aCGH analysis revealed arr 21q11.2q22.3 × 2.48, and interphase fluorescence in situ hybridization (FISH) analysis revealed 39% (39/100 cells) mosaicism fro trisomy 21 in uncultured amniocytes. At 36 weeks of gestation, the woman suffered from a sudden onset of acute fatty liver and IUFD. A 3522-g male baby was delivered without Down syndrome phenotype. The umbilical cord had a karyotype of 47,XY,+21[10]/46,XY[30]. aCGH analysis on the skin and placenta showed arr 21q11.2q22.3 × 2.73 and arr 21q11.2q22.3 × 2.75, respectively. QF-PCR analysis of umbilical cord, placenta and skin showed a maternal origin of trisomy 21. CONCLUSION: High-level mosaic trisomy 21 at amniocentesis can be associated with prenatal progressive decrease of the trisomy 21 cell line in cultured amniocytes and perinatal fetal mortality and maternal morbidity.

45,X/46,XX at the first amniocentesis, and 45,X/47,XXX/46,XX at the repeat amniocentesis and at birth in a pregnancy associated with a favorable fetal outcome, perinatal progressive decrease of the 45,X cell line and cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes.

OBJECTIVE: We present 45,X/46,XX at the first amniocentesis, and 45,X/47,XXX/46,XX at the repeat amniocentesis and at birth in a pregnancy associated with a favorable fetal outcome, perinatal progressive decrease of the 45,X cell line and cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes. CASE REPORT: A 43-year-old, gravida 3, para 1, woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 45,X[4]/46,XX[20]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed arr (X) × 3 [0.24], consistent with 24% mosaicism for triple X. Repeat amniocentesis at 20 weeks of gestation revealed the result of 45,X[17]/47,XXX[8]/46,XX[121]. She was referred for genetic counseling, and the third amniocentesis performed at 30 weeks of gestation revealed the result of 45,X[3]/47,XXX[2]/46,XX[16]. The mother had a karyotype of 46,XX. aCGH analysis on the DNA extracted from uncultured amniocytes showed arr Xp22.33q28 × 2.2 (log2 ratio = 0.15), consistent with 20% mosaicism for triple X. Interphase fluorescence in situ hybridization (FISH) analysis on 100 uncultured amniocytes showed that 11 cells (11%) were monosomy X, seven cells (7%) were triple X, and the others were disomy X. At 39 weeks of gestation, a 3,620-g phenotypically normal female baby was delivered without any phenotypic abnormality. The karyotypes of cord blood, umbilical cord and placenta were 47,XXX[7]/45,X[1]/46,XX[32], 47,XXX[13]/46,XX[27] and 47,XXX[2]/46,XX[38], respectively. When follow-up at age one month, the neonate was phenotypically normal, and FISH analysis on 106 buccal mucosal cells showed that eight cells (7.5%) were monosomy X, seven cells (6.6%) were triple X, and the others were disomy X. CONCLUSION: Mosaic 45,X/46,XX at amniocentesis may be in fact mosaic 45,X/47,XXX/46,XX and can be associated with a favorable fetal outcome and perinatal progressive decrease of the 45,X cell line.

Perinatal detection of disomy X cell line by fluorescence in situ hybridization in a pregnancy with 45,X/47,XXX at amniocentesis, cytogenetic discrepancy in various tissues and a favorable outcome.

OBJECTIVE: We present perinatal detection of disomy X cell line by fluorescence in situ hybridization (FISH) in a pregnancy with 45,X/47,XXX at amniocentesis, cytogenetic discrepancy in various tissues and a favorable outcome. CASE REPORT: A 34-year-old, gravida 3, para 1, woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 45,X[22]/47,XXX[10]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr (X) × 1-2, (1-22) × 2, consistent with 32% mosaicism for monosomy X. She was referred for genetic counseling at 19 weeks of gestation. Prenatal ultrasound findings and parental karyotypes were normal. Repeat amniocentesis at 29 weeks of gestation revealed a karyotype of 45,X[36]/47,XXX[4] (Fig. 1) in cultured amniocytes. Simultaneous molecular analysis on uncultured amniocytes revealed the result of arr (1-22) × 2, Y × 0 by aCGH with no genomic imbalance, and 15% (15/100 cells) mosaicism for disomy X, 61% (61/100 cells) mosaicism for monosomy X and 24% (24/100 cells) mosaicism for triple X by interphase fluorescence in situ hybridization (FISH) analysis. The pregnancy was encouraged to continue and at 37 weeks of gestation, a 2834-g phenotypically normal female baby was delivered. The karyotypes of cord blood, umbilical cord and placenta were 45,X[33]/47,XXX[7], 45,X[30]/47,XXX[10] and 47,XXX[38]/45,X[2], respectively. When follow-up at age three months, the neonate was normal in development. FISH analysis on 99 buccal mucosal cells showed 49% (48/99 cells) mosaicism for monosomy X, 8% (8/99 cells) mosaicism for triple X and 43% (42/99 cells) mosaicism for disomy X (Fig. 2). Peripheral blood had a karyotype of 45,X[38]/47,XXX[2]. When follow-up at age nine months, the neonate was normal in development. FISH analysis on 102 buccal mucosal cells showed 11% (11/102 cells) mosaicism for monosomy X, 12% (12/102 cells) mosaicism for triple X and 77% (79/102 cells) mosaicism for disomy X. Peripheral blood had a karyotype of 45,X[30]/47,XXX[10]. CONCLUSION: 45,X/47,XXX at amniocentesis may detect disomy X cell line by FISH analysis and can be associated with postnatal progressive decrease of the aneuploid cell lines, increase of the disomy X cell line and a favorable outcome.

Low-level mosaic trisomy 21 at amniocentesis in a pregnancy associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy 21 at amniocentesis in a pregnancy with a favorable fetal outcome. CASE REPORT: A 34-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 47,XY,+21 [7]/46,XY [33]. At 23 weeks of gestation, repeat amniocentesis revealed a karyotype of 47,XY,+21 [4]/46,XY [22], and cord blood sampling revealed the karyotype of 47,XY,+21 [5]/46,XY [35]. The parental karyotypes were normal. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on uncultured amniocytes and parental bloods excluded UPD 21, array comparative genomic hybridization (aCGH) analysis on uncultured amniocytes revealed the result of arr 21q11.2q22.3 × 2.3, consistent with 30% mosaicism for trisomy 21. Interphase fluorescence in situ hybridization (FISH) analysis on uncultured amniocytes revealed 43.8% (35/80 cells) mosaicism for trisomy 21. The woman was advised to continue the pregnancy, and a phenotypically normal 3,340-g male baby was delivered at 39 weeks of gestation. The cord blood had a karyotypes of 46,XY (40/40 cells). QF-PCR on placenta showed mosaic trisomy 21. When follow-up at age three months, the neonate was normal in phenotype and development. FISH analysis on buccal mucosal cells showed 9% (10/101 cells) mosaicism for trisomy 21, compared with 0% (0/100 cells) in the normal control. CONCLUSION: Low-level mosaic trisomy 21 at amniocentesis can be associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.

Genetic counseling of a prenatally detected familial 18.79-kb Xp21.1 microduplication encompassing exon 13 of DMD in a pregnancy with no apparent phenotypic abnormalities in the male carriers in the family.

OBJECTIVE: We present genetic counseling of a prenatally detected familial 18.79-kb Xp21.1 microduplication encompassing exon 13 of DMD in a pregnancy with no apparent phenotypic abnormalities in the male carriers in the family. CASE REPORT: A 35-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. Simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes revealed an 18.79-kb Xp21.1 microduplication, or arr Xp21.1 (32,608,400-32,627,193) × 2.0 [GRCh37 (hg19)] encompassing only exon 13 of the gene of DMD (31,137,345-33,357,706) [GRCh37 (hg19)]. Multiplex ligation-dependent probe amplification (MLPA) analysis of the family showed that the mother and her 32-year-old brother carried the same duplication but without apparent phenotypic abnormalities and no features of DMD. Prenatal ultrasound was normal. She was referred for genetic counseling at 24 weeks of gestation, and continuing pregnancy was advised. At 38 weeks of gestation, a 3530-g phenotypically normal male baby was delivered. aCGH analysis of the umbilical cord confirmed the result of arr Xp21.1 (32,608,400-32,627,193) × 2.0 [GRCh37 (hg19)] encompassing only exon 13 of the gene of DMD (31,137,345-33,357,706) [GRCh37 (hg19)]. CONCLUSION: Xp21.1 microduplication encompassing exon 13 of the DMD gene can be a benign genetic variant.

High-level mosaicism for 45,X in 45,X/46,X,+mar at amniocentesis in a pregnancy associated with positive non-invasive prenatal testing for Turner syndrome, normal male external genitalia and positive SRY in the fetus, a favorable fetal outcome, postnatal decrease of the 45,X cell line and cytogenetic discrepancy in various tissues.

OBJECTIVE: We present high-level mosaicism for 45,X in 45,X/46,X,+mar at amniocentesis in a pregnancy associated with positive non-invasive prenatal testing (NIPT) for Turner syndrome, normal male external genitalia and positive SRY in the fetus, a favorable fetal outcome, postnatal decrease of the 45,X cell line and cytogenetic discrepancy in various tissues. CASE REPORT: A 35-year-old, gravida 2, para 1, woman underwent amniocentesis at 16 weeks of gestation because of positive NIPT for Turner syndrome (Z score = -11.72 for X chromosome) at 10 weeks of gestation. Amniocentesis revealed a karyotype of 45,X[13]/46,X,+mar[8]. Simultaneous molecular analysis on the DNA extracted from uncultured amniocytes revealed the results of arr (X) × 1, (Yp) × 0-1 (0.63), (Yq) × 0, (1-22) × 2 in array comparative genomic hybridization (aCGH) and rsa(X) × 1, Yp11.31 × 0-1, Yq11.21 × 0, (13, 18, 21) × 2 in multiplex ligation-dependent probe amplification (MLPA). The parental karyotypes were normal. Prenatal ultrasound revealed normal male external genitalia. She was referred for genetic counseling, and continuing pregnancy was advised. A 2875-g male baby was delivered at 38 weeks of gestation with normal male external genitalia. The karyotypes of cord blood, umbilical cord and placenta were 46,X,+mar[27]/45,X[13], 46,X,+mar[24]/45,X[16] and 45,X[22]/46,X,+mar[18], respectively. SRY testing on cord blood revealed a positive result. When follow-up at age two months, the neonate was normal in development. The karyotype of peripheral blood was 46,X,+mar[25]/45,X[13]/46,X,idic r(Y) [2]. Interphase fluorescence in situ hybridization (FISH) analysis on 103 buccal mucosal cells using Yp11.2-specific probe RP11-119E4 and Xp22.31-specific probe RP11-143E20 showed that 90 cells (90/103 = 87%) had double Yp signals, 3 cells (3/103 = 3%) had single Yp signal and 10 cells (10/103 = 10%) had no Yp signal. CONCLUSION: High-level mosaicism for 45,X in 45,X/46,X,+mar at amniocentesis with positive Yp and SRY can be associated with a favorable fetal outcome, postnatal decrease of the 45,X cell line and cytogenetic discrepancy in various tissues.

Mosaicism for a 12p12.1p12.2 microdeletion with a normal euploid cell line at amniocentesis in a pregnancy with a favorable outcome and postnatal decrease of the aneuploid cell line with microdeletion.

OBJECTIVE: We present mosaicism for a 12p12.1p12.2 microdeletion with a normal euploid cell line at amniocentesis in a pregnancy with a favorable outcome and postnatal decrease of the aneuploid cell line with microdeletion. CASE REPORT: A 35-year-old woman, gravida 2, para 1, underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed mosaic 46,XY,del (12) (p11.2p12), and array comparative genomic hybridization (aCGH) revealed arr Xp22.31 × 2 mat, 12p12.2p12.1 × 1 [0.36]dn with a 4.15-Mb 36% mosaicism for a 12p12.1p12.2 microdeletion. At 22 weeks of gestation, she underwent cord blood sampling of which aCGH revealed arr Xp22.31 × 2 mat, 12p12.2p12.1 × 1 [0.34]dn with a 4.24-Mb 34% mosaicism for a 12p12.1p12.2 microdeletion. Prenatal ultrasound findings were unremarkable. She was referred for genetic counseling, and continuing pregnancy was advised. A 2990-g male baby was delivered at 38 weeks of gestation with no phenotypic abnormality. When follow-up at age 1½ months, the neonate was phenotypically normal. The karyotype of peripheral blood was 46,XY. aCGH analysis on the DNA extracted from peripheral blood revealed the result of arr 12p12.1p12.2 (20, 367, 240-24,489,386) × 1.87, arr Xp22.31 (6,488,721-8,097,511) × 2.0 [GRCh37 (hg19)] with 10-15% (log2 ratio = 0.1) mosaicism for a 4.122-Mb 12p12.1-p12.2 microdeletion encompassing 17 OMIM genes of PDE3A, SLCO1C1, SLCO1B3, SLCO1B1, IAPP, PYROXD1, RECQL, GOLT1B, SPX, GYS2, LDHB, KCNJ8, ABCCP, CMAS, C2CD5, ETNK1 and SOX5 and a 1.609-Mb Xp22.31 duplication encompassing two OMIM genes of STS and VCX. Interphase fluorescence in situ hybridization (FISH) analysis on 104 buccal mucosal cells using 12p12.1-specific probe showed 17% (18/104 cells) mosaicism for a 12p12.1 deletion. Polymorphic DNA marker analysis on the DNA extracted from proband's blood and parental bloods determined a paternal origin of the mosaic 12p12.1 deletion. CONCLUSION: Mosaicism for a 12p12.1p12.2 microdeletion at amniocentesis with a normal euploid cell line can be a benign condition in association with a favorable fetal outcome and postnatal decrease of the aneuploid cell line with microdeletion.

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 amniocytes and uncultured amniocytes, intrauterine growth restriction and a favorable fetal outcome.

OBJECTIVE: 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. CASE REPORT: 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. CONCLUSION: 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.

Low-level mosaic trisomy 13 at amniocentesis in a pregnancy associated with a positive NIPT result suspicious of trisomy 13, a CVS result of mosaic trisomy 13, cytogenetic discrepancy in various tissues and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy 13 at amniocentesis in a pregnancy associated with a positive non-invasive prenatal testing (NIPT) result suspicious of trisomy 13, a chorionic villus sampling (CVS) result of mosaic trisomy 13, cytogenetic discrepancy in various tissues and a favorable fetal outcome. CASE REPORT: A 29-year-old, gravida 2, para 1, woman underwent amniocentesis at 20 weeks of gestation because of a positive NIPT result (Z-score = 20.9, positive ≥3) suspicious of trisomy 13 at 11 weeks of gestation and a CVS result of mosaic trisomy 13 at 14 weeks of gestation. At 14 weeks of gestation, CVS revealed the multiplex ligation-dependent probe amplification (MLPA) result of rea X,Y (P095) × 1, 13 (P095) × 3, 18,21 (P095) × 2/X,Y (P095) × 1, 13,18,21 (P095) × 2 and a karyotype of 48,XY,+13,+mar [9]/47,XY,+mar[16]. She was referred to the hospital for genetic counseling at 15 weeks of gestation, and cytogenetic analysis of parental blood revealed 47,XY,+mar in the father and 46, XX in the mother. Fluorescence in situ hybridization (FISH) analysis on the paternal blood showed that the extra dicentric marker was derived from chromosome 15 without the locus SNRPN (15q11.2), and the result was 47,XY,+mar.ish dic(15) (D15Z1++, SNRPN-, PML-)[20]. Amniocentesis at 20 weeks of gestation revealed a karyotype of 47,XY,+mar pat (20/20). Simultaneous interphase FISH analysis on uncultured amniocytes revealed 32% (32/100 cells) mosaicism for trisomy 13. Quantitative fluorescence polymerase chain reaction (QF-PCR) analysis using the DNA extracted from the parental bloods and uncultured amniocytes excluded uniparental disomy (UPD) 13. Prenatal ultrasound findings were normal. The woman was advised to continue the pregnancy, and a phenotypically normal 2708-g male baby was delivered at 38 weeks of gestation, The cord blood, umbilical cord and placenta had the karyotypes of 47,XY,+mar pat and did not have UPD 13. When follow-up at age two months, the neonate was phenotypically normal. FISH analysis on buccal mucosal cells detected 5.3% (5/95 cells) mosaicism for trisomy 13, compared with 0% in the normal control. CONCLUSION: Low-level mosaic trisomy 13 at amniocentesis can be associated with a positive NIPT result suspicious of trisomy 13, a CVS result of mosaic trisomy 13, cytogenetic discrepancy in various tissues and a favorable fetal outcome.

Low-level mosaic trisomy 21 at amniocentesis in a pregnancy associated with a negative NIPT result, cytogenetic discrepancy in various tissues, perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy 21 at amniocentesis associated with a favorable fetal outcome. CASE REPORT: A 31-year-old primigravid woman underwent non-invasive prenatal testing (NIPT) at 12 weeks of gestation, and the result was normal. She underwent amniocentesis at 16 weeks of gestation because of fetal choroid plexus cyst, and the result was 47,XX,+21[5]/46,XX[32]. Repeat amniocentesis was performed at 19 weeks of gestation, and the result was 47,XX,+21[5]/46,XX[15]. Simultaneous array comparative genomic hybridization (aCGH) analysis on uncultured amniocytes revealed the result of arr (21) × 3 [0.10], consistent with 10% mosaicism for trisomy 21. Prenatal ultrasound findings were unremarkable. She was referred for genetic counseling at 22 weeks of gestation, and the third amniocentesis was performed at 25 weeks of gestation, and the result was 46,XX (20/20 colonies). The parental karyotypes were normal. Simultaneous quantitative fluorescence polymerase chain reaction (QF-PCR) analysis on the DNA extracted from uncultured amniocytes and parental bloods excluded uniparental disomy (UPD) 21. aCGH analysis on uncultured amniocytes revealed arr 21q11.2q22.3 × 2.1 (log2 ratio = 0.1), consistent with 10-15% mosaicism for trisomy 21. Fluorescence in situ hybridization (FISH) analysis on uncultured amniocytes revealed 30% (30/100 cells) mosaicism for trisomy 21. The woman was advised to continue the pregnancy, and a phenotypically normal 2800-g female baby was delivered at 38 weeks of gestation. The karyotype of cord blood, umbilical cord and placenta were 47,XX,+21[1]/46,XX[39]. 47,XX,+21[4]/46,XX[36] and 46,XX (40/40 cells), respectively. When follow-up at age two months, the neonate was phenotypically normal. The peripheral blood had a karyotype of 47,XX,+21[1]/46,XX[39], and FISH analysis on buccal mucosal cells revealed 8.4% (7/83 cells) mosaicism for trisomy 21, compared with 0% in the normal control. CONCLUSION: Low-level mosaic trisomy 21 at amniocentesis can be associated with a negative NIPT result, cytogenetic discrepancy in various tissues, perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.

45,X/46,XX at amniocentesis associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes and in different amniocenteses and a favorable fetal outcome with a normal karyotype at birth.

OBJECTIVE: We present 45,X/46,XX at amniocentesis associated with cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes and in different amniocenteses and a favorable fetal outcome with a normal karyotype at birth. CASE REPORT: A 35-year-old, gravida 3, para 2, woman underwent amniocentesis at 20 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 45,X[11]/46,XX[108], consistent with 9.2% mosaicism for 45,X. Prenatal ultrasound findings were unremarkable. She was referred for genetic counseling at 25 weeks of gestation, and repeat amniocentesis at 26 weeks of gestation revealed a karyotype of 45,X[4]/46,XX[16], consistent with 20% mosaicism for 45,X. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes using SurePrint G3 Unrestricted CGH ISCA v2, 8 × 60K (Agilent Technologies, Santa Clara, CA, USA) revealed arr (1-22, X) × 2, Y × 0 with no genomic imbalance. The woman was advised to continue pregnancy, and at 38 weeks of gestation, a healthy 3140-g female baby was delivered with no phenotypic abnormalities. The cord blood had a karyotype of 46,XX (40/40 cells). When follow-up at age two months, the neonate had normal development and a normal karyotype. CONCLUSION: Confirmation of 45,X/46,XX at amniocentesis should include conventional cytogenetic analysis and karyotyping on cultured amniocytes, and sole molecular analysis on uncultured amniocytes may miss the diagnosis of 45,X/46,XX.

Mosaicism for Robertsonian jumping translocation at amniocentesis: 45,XY,der(15;22)(q10;q10)mat/46,XY,i(15)(q10)/46,XY, genetic counseling, prenatal diagnosis and postnatal follow-up in a pregnancy with a favorable fetal outcome.

OBJECTIVE: We present genetic counseling, prenatal diagnosis and postnatal follow-up of 45,XY,der(15;22)(q10;q10)mat/46,XY,i(15)(q10)/46,XY at amniocentesis in a pregnancy with a favorable fetal outcome. CASE REPORT: A 27-year-old, primigravid woman underwent amniocentesis at 19 weeks of gestation because increased nuchal translucency thickness, and the result was 45,XY,der(15;22)(q10;q10)[29]/46,XY,i(15)(q10)[3]/46,XY[5]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed arr (1-22) × 2, (X,Y) × 1. The maternal karyotype was 45,XX,der(15;22)(q10;q10), and the paternal karyotype was 46,XY. She was referred for genetic counseling, and repeat amniocentesis performed at 23 weeks of gestation revealed 45,XY,der(15;22)(q10;q10)mat[23]/45,XY,-22[2]. aCGH analysis on uncultured amniocytes detected no genomic imbalance, and polymorphic DNA marker analysis excluded uniparental disomy (UPD) 15. Fluorescence in situ hybridization (FISH) analysis using the chromosome 15q specific probe and the chromosome 22q specific probe detected three 15q signals in 4/104 cells (3.8%). The woman was advised to continue the pregnancy, and, a 3186-g phenotypically normal male baby was delivered at 38 weeks of gestation. The umbilical cord had a karyotype of 45,XY,der(15;22)(q10;q10) (40/40 cells). When follow-up at age seven months, the neonate was normal in development, the peripheral blood had a karyotype of 45,XY,der(15;22)(q10;q10) (40/40 cells), and the buccal mucosal cells had normal signals in all 100 cells. CONCLUSIONS: Mosaicism for Robertsonian jumping translocations at amniocentesis can be a transient condition and can be associated with a familial Robertsonian translocation and a favorable fetal outcome. Prenatal diagnosis of a Robertsonian jumping translocation involving chromosome 15 should include UPD 15 testing to exclude UPD 15.

Mosaic trisomy 16 at amniocentesis in a pregnancy associated with positive non-invasive prenatal testing for trisomy 16, placental trisomy 16, intrauterine growth restriction, intrauterine fetal death, cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, and prenatal progressive decrease of the aneuploid cell line.

OBJECTIVE: We present mosaic trisomy 16 at amniocentesis in a pregnancy associated with positive non-invasive prenatal testing (NIPT) for trisomy 16, placental trisomy 16, intrauterine growth restriction (IUGR), intrauterine fetal death (IUFD), cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes and uncultured amniocytes, and prenatal progressive decrease of the aneuploid cell line. CASE REPORT: A 26-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of positive NIPT for trisomy 16 at 12 weeks of gestation. Amniocentesis revealed a karyotype of 47,XX,+16 [10]/46,XX[17], and simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr (16) × 3 [0.43] consistent with 43% mosaicism for trisomy 16. She was referred for genetic counseling at 19 weeks of gestation, and a fetus with IUGR was noted to have a size equivalent to 16 weeks of gestation. At 23 weeks of gestation, the fetus manifested oligohydramnios, fetal cardiomegaly and severe IUGR (fetal size equivalent to 20 weeks of gestation). Repeat amniocentesis revealed a karyotype of 46,XX (20/20 colonies) in cultured amniocytes and mosaic trisomy 16 by aCGH in uncultured amniocytes. aCGH analysis on uncultured amniocytes revealed the result of arr 16p13.3q24.3 × 2.3, consistent with 30% (log2 ratio = 0.2) mosaicism for trisomy 16. Quantitative fluorescence polymerase chain reaction (QF-PCR) assays on the DNA extracted from parental bloods and uncultured amniocytes excluded uniparental disomy (UPD) 16. The parental karyotypes were normal. IUFD was noted at amniocentesis. The pregnancy was subsequently terminated, and a 288-g female fetus was delivered with no phenotypic abnormalities. The umbilical cord had a karyotype of 46,XX (40/40 cells), and the placenta had a karyotype of 47,XX,+16 (40/40 cells). QF-PCR assays of the placenta confirmed a maternal origin of trisomy 16. CONCLUSION: Mosaic trisomy 16 at amniocentesis can be associated with positive NIPT for trisomy 16, placental trisomy 16, IUGR, IUFD, cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes, and prenatal progressive decrease of the aneuploid cell line.

High-level mosaic trisomy 14 at amniocentesis in a pregnancy associated with congenital heart defects and intrauterine growth restriction on fetal ultrasound.

OBJECTIVE: We present high-level mosaic trisomy 14 at amniocentesis in a pregnancy associated with congenital heart defects (CHD) and intrauterine growth restriction (IUGR). CASE REPORT: A 34-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,XX,+14[9]/46,XX[13], consistent with 40.9% (9/22 colonies) mosaicism for trisomy 14. Simultaneous array comparative genomic hybridization (aCGH) on the DNA extracted from uncultured amniocytes revealed 61% mosaicism for trisomy 14. Prenatal ultrasound at 22 weeks of gestation showed a malformed fetus with double outlet of right ventricle (DORV), ventricular septal defect (VSD), pulmonary stenosis and severe IUGR with the growth parameters equivalent to 18 weeks of gestation. The pregnancy was terminated at 23 weeks of gestation, and a 278-g female fetus was delivered with facial dysmorphism of hypertelorism, low-set small ears and wide depressed nasal bridge. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from parental bloods, cord blood, umbilical cord and placenta confirmed a maternal origin of the extra chromosome 14 and excluded uniparental disomy (UPD) 14. The umbilical cord had a karyotype of 47,XX,+14[7]/ 46,XX[13], and the placenta had a karyotype of 47,XX,+14[4]/46,XX[36]. CONCLUSIONS: High-level mosaic trisomy 14 at amniocentesis can be associated with abnormal ultrasound findings of CHD and IUGR.

Mosaicism for a 15q11.2 microduplication with a normal euploid cell line at amniocentesis in a pregnancy with a favorable fetal outcome and postnatal decrease of the aneuploid cell line with the microduplication.

OBJECTIVE: We present mosaicism for a 15q11.2 microduplication with a normal euploid cell line at amniocentesis in a pregnancy with a favorable fetal outcome and postnatal decrease of the aneuploid cell line with the microduplication. CASE REPORT: A 35-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed 33.76% mosaicism for a 15q11.2 microduplication. She was referred for genetic counseling. Repeat amniocentesis was performed at 23 weeks of gestation, and the karyotype was 46,XY. Simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes revealed the result of arr [GRCh37 (hg19)] 15q11.2 (23, 889, 686-25,514,125) × 2.45, consistent with a mosaic 1.624-Mb microduplication with the mosaic level of 40%-45% (log2 ratio = 0.28) encompassing nine OMIM genes of MAGEL2, NDN, PWRN2, PWRN1, NPAP1, SNRPN, SNHG14, SNORD116-1 and SNORD115-1. Interphase fluorescence in situ hybridization (FISH) analysis on 100 uncultured amniocytes detected a 15q11.2 duplication in 19 cells, consistent with 19% (19/100 cells) mosaic15q11.2 duplication. Polymorphic DNA marker analysis excluded uniparental disomy (UPD) 15. Prenatal ultrasound findings were unremarkable. She was advised to continue the pregnancy, and a 3865-g phenotypically normal male baby was delivered. aCGH analysis on the DNA extracted from cord blood at birth and buccal mucosal cells at age four months revealed arr (1-22) × 2, X × 1, Y × 1 and detected no genomic imbalance in all samples. Interphase FISH analysis on 104 buccal mucosal cells at age four months detected four cells (4/104 = 4%) with a 15q11.2 duplication, compared with 0% (0/102 cells) in the normal control. The neonate was normal in the development. CONCLUSION: Mosaicism for a 15q11.2 microduplication at amniocentesis with a normal euploid cell line can be a benign condition and associated with a favorable fetal outcome and postnatal decrease of the aneuploid cell line with the microduplication.

Prenatal diagnosis of mosaic trisomy 18 and maternal uniparental disomy 18 by amniocentesis in a pregnancy associated with cytogenetic discrepancy in various tissues and a favorable fetal outcome.

OBJECTIVE: We present prenatal diagnosis of mosaic trisomy 18 and maternal uniparental disomy (UPD) 18 in a pregnancy with a favorable fetal outcome. CASE REPORT: A 34-year-old woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age, and the result was 47,XY,+18 [4]/46,XY [25] in cultured amniocytes. Simultaneous array comparative genomic hybridization (aCGH) on uncultured amniocytes revealed 65% mosaicism for trisomy 18. Prenatal ultrasound was normal. She consulted our hospital and underwent repeat amniocentesis at 22 weeks of gestation, and the result revealed a karyotype of 47,XY,+18 [9]/46,XY [12] in cultured amniocytes. Simultaneous aCGH on uncultured amniocytes revealed arr 18p11.32q23 × 2.4 (log2 ratio = 0.3) consistent with 40% mosaicism for trisomy 18. Parental karyotypes were normal. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from parental bloods and uncultured amniocytes confirmed maternal uniparental heterodisomy of chromosome 18. At 26 weeks of gestation, she underwent the third amniocentesis which revealed a karyotype of 47,XY,+18 [7]/46,XY [19] in cultured amniocytes. Simultaneous aCGH on uncultured amniocytes revealed arr 18p11.32q23 × 2.4 (log2 ratio = 0.27) consistent with 40% mosaicism for trisomy 18. Interphase fluorescence in situ hybridization (FISH) on uncultured amniocytes revealed 38% (38/100 cells) mosaicism for trisomy 18. The woman was advised to continue the pregnancy, and a 2620-g phenotypically normal male baby was delivered at 40 weeks of gestation. At birth, the karyotypes of cord blood, umbilical cord and placenta were 47,XY,+18 [14]/46,XY [26], 47,XY,+18 [9]/46,XY [31] and 47,XY,+18 (40/40 cells), respectively. When follow-up at age 2½ months, the neonate was phenotypically normal. The peripheral blood had a karyotype of 47,XY,+18 [28]/46,XY [12], and interphase FISH analysis on buccal mucosal cells detected 6.4% (7/93 cells) mosaicism for trisomy 18, compared with 0% (0/100 cells) in the normal control. When follow-up at age seven months, the neonate was normal in development, and the peripheral blood had a karyotype of 47,XY,+18 [18]/46,XY [22]. CONCLUSIONS: Mosaic trisomy 18 at amniocentesis can be associated with cytogenetic discrepancy in various tissues, UPD 18 and a favorable fetal outcome. Prenatal diagnosis of mosaic trisomy 18 should alert the possibility of UPD 18 and include UPD testing.