Increased Diagnostic Yield of Array Comparative Genomic Hybridization for Autism Spectrum Disorder in One Institution in Taiwan.

Background and Objectives: Chromosomal microarray offers superior sensitivity for identification of submicroscopic copy number variants (CNVs) and is recommended for the initial genetic testing of patients with autism spectrum disorder (ASD). This study aims to determine the diagnostic yield of array comparative genomic hybridization (array-CGH) in ASD patients from a cohort of Chinese patients in Taiwan. Materials and Methods: Enrolled in this study were 80 ASD children (49 males and 31 females; 2-16 years old) followed up at Taipei MacKay Memorial Hospital between January 2010 and December 2020. The genomic DNA extracted from blood samples was analyzed by array-CGH via the Affymetrix GeneChip Genome-Wide Human single nucleotide polymorphism (SNP) and NimbleGen International Standards for Cytogenomic Arrays (ISCA) Plus Cytogenetic Arrays. The CNVs were classified into five groups: pathogenic (pathologic variant), likely pathogenic (potential pathologic variant), likely benign (potential normal genomic variant), benign (normal genomic variant), and uncertain clinical significance (variance of uncertain significance), according to the American College of Medical Genetics (ACMG) guidelines. Results: We identified 47 CNVs, 31 of which in 27 patients were clinically significant. The overall diagnostic yield was 33.8%. The most frequently clinically significant CNV was 15q11.2 deletion, which was present in 4 (5.0%) patients. Conclusions: In this study, a satisfactory diagnostic yield of array-CGH was demonstrated in a Taiwanese ASD patient cohort, supporting the clinical usefulness of array-CGH as the first-line testing of ASD in Taiwan.

Prenatal diagnosis and molecular cytogenetic characterization of a de novo pure distal 9p deletion and literature review.

We present rapid aneuploidy diagnosis of distal 9p deletion by array comparative genomic hybridization using uncultured amniocytes in a pregnancy associated with an abnormal maternal serum screening result and intrauterine growth restriction (IUGR) in the fetus. We review the literature of prenatal diagnosis of distal 9p deletion, and add abnormal maternal serum biochemistry and fetal IUGR in the distinctive prenatal findings in pregnancy with fetal distal 9p deletion. We discuss the consequence of haploinsufficiency of DOCK8, KANK1, VLDLR and DMRT1 in this case.

Prenatal diagnosis of familial 3p26.3p25.3 deletion in a pregnancy associated with a favorable fetal outcome and asymptomatic carrier parent and family members in three generations.

OBJECTIVE: We present prenatal diagnosis of familial 3p26.3p25.3 deletion in a pregnancy associated with a favorable fetal outcome and asymptomatic carrier parent and family members in three generations. CASE REPORT: A 35-year-old, gravida 2, para 1, woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age and the carrier of distal 3p deletion. She was phenotypically normal, and there was no family history of congenital anomalies. Amniocentesis revealed a karyotype of 46,XY,del(3)(p26.1). Repeat amniocentesis at 21 weeks of gestation revealed a karyotype of 46,XY,del(3)(p25.3). Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes showed the result of arr 3p26.3p25.3 (117,735-8,709,972) × 1.0 [GRCh37 (hg19)] with an 8.59-Mb deletion of 3p26.3p25.3 encompassing 14 OMIM genes of CHL1, CNTN6, CNTN4, IL5RA, TRNT1, CRBN, SETMAR, SUMF1, ITPR1, BHLHE40, ARL8B, GRM7, LMCD1 and SSUH2. Cytogenetic analysis of parental bloods revealed a karyotype of 46,XX,del (3) (p25.3) in the mother and 46,XY in the father. The woman's 69-year-old mother and her 2-year-old elder son carried the same aberrant chromosome of 3p25.3→p26.3 deletion by conventional cytogenetic analysis but manifested no phenotypic abnormality. aCGH analysis of the peripheral bloods showed that the woman's mother and her elder son had the same 8.59-Mb deletion of 3p26.3p25.3. The woman was advised to continue the pregnancy. At 39 weeks of gestation, a 3040-g healthy male baby was delivered. When follow-up at age 2½ years, the neonate was normal in development and showed no apparent phenotypic abnormality. CONCLUSION: Distal 3p deletion of 3p26.3p25.3 involving the OMIM genes from CHL1 to SSUH2 can be associated with no apparent phenotypic abnormality.

Prenatal diagnosis of a de novo 10p12.1p11.23 microdeletion encompassing the WAC gene in a fetus associated with bilateral hydronephrosis and right clubfoot on prenatal ultrasound.

OBJECTIVE: We present prenatal diagnosis of de novo 10p12.1p11.23 microdeletion encompassing the WAC gene in a fetus associated with bilateral hydronephrosis on prenatal ultrasound. CASE REPORT: A 40-year-old, gravida 2, para 1, woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY. Level II ultrasound at 22 weeks of gestation revealed bilateral hydronephrosis and right clubfoot. At 23 weeks of gestation, repeat amniocentesis revealed the result of arr [GRCh37] 10p12.1p11.23 (26,182,512-29,826,276) × 1 dn with a 3.6-Mb microdeletion of 10p12.1p11.23 encompassing the genes of MYO3A, GAD2, APBB1IP, PDSS1, ABI1, ANKRD26, YME1L1, MASTL, ACBD5, PTCHD3, RAB18, MKX, ODAD2, MPP7, WAC and BAMBI. The pregnancy was subsequently terminated, and a malformed fetus was delivered with facial dysmorphism of low-set ears, broad forehead and flat nasal bridge. Array comparative genomic hybridization (aCGH) analysis of umbilical cord confirmed a 3.6-Mb 10p12.1p11.23 microdeletion encompassing WAC. CONCLUSION: Application of aCGH is useful in the pregnancy with a normal fetal karyotype and abnormal fetal ultrasound.

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.

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.

Low-level mosaic trisomy 21 at amniocentesis and cordocentesis in the second trimester in a pregnancy associated with positive non-invasive prenatal testing for trisomy 21, perinatal progressive decrease of the trisomy 21 cell line and a favorable fetal outcome.

OBJECTIVE: We present low-level mosaic trisomy 21 at amniocentesis and cordocentesis in a pregnancy associated with a favorable fetal outcome. CASE REPORT: A 26-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of positive non-invasive prenatal testing (NIPT) for trisomy 21 at 16 weeks of gestation. Amniocentesis revealed a karyotype of 47,XX,+21[3]/46,XX[17], and multiplex ligation-dependent probe amplification (MLPA) on uncultured amniocytes revealed rsa X(P095) × 2, (13, 18, 21) × 2. She underwent cordocentesis (cord blood sampling) at 21 weeks of gestation which revealed a karyotype of 47,XX,+21[2]/46,XX[48]. At 27 weeks of gestation, she was referred to our hospital for genetic counseling, and repeat amniocentesis revealed a karyotype of 46,XX in 20/20 colonies. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from uncultured amniocytes and parental bloods excluded uniparental disomy (UPD) 21. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed arr (1-22,X) × 2, Y × 0 with no genomic imbalance. Interphase fluorescence in situ hybridization (FISH) analysis on 104 uncultured amniocytes detected one cell (1/104 = 0.9%) with trisomy 21, while the rest cells were disomy 21, compared with 0% (0/100) in the normal control. The woman was encouraged to continue the pregnancy. The pregnancy was carried to 38 weeks of gestation, and a 2771-g female baby was delivered no phenotypic abnormality. aCGH analysis on the cord blood showed arr (1-22,X) × 2, Y × 0 with no genomic imbalance. The umbilical cord had a karyotype of 47,XX,+21[3]/46,XX[37]. The placenta had a karyotype of 46,XX. When follow-up at age 3½ months, the neonate was phenotypically normal and had normal development. The peripheral blood had a karyotype of 46,XX in 40/40 cells. Interphase FISH analysis on buccal mucosal cells detected normal disomy 21 cells in 100/100 cells. CONCLUSION: Low-level mosaic trisomy 21 at amniocentesis and cordocentesis in the second trimester can be associated with perinatal progressive decrease of the trisomy 21 cell line and a favorable fetal 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 trisomy 21 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 38-year-old, gravida 2, para 1, woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 47,XY,+21[4]/46,XY[34]. Prenatal ultrasound findings were normal. At 27 weeks of gestation, she was referred for genetic counseling, and the cultured amniocytes had a karyotype of 47,XY,+21[2]/46,XY[26]. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from uncultured amniocytes and parental bloods excluded uniparental disomy (UPD) 21. Interphase fluorescence in situ hybridization (FISH) analysis on uncultured amniocytes revealed 30% (30/100 cells) mosaicism for trisomy 21. Array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr 21q11.2q22.3 × 2.25, consistent with 20%-30% mosaicism for trisomy 21. The parental karyotypes were normal. The woman was advised to continue the pregnancy, and a 3510-g phenotypically normal male baby was delivered at 39 weeks of gestation. Cytogenetic analysis of the cord blood, umbilical cord and placenta revealed the karyotypes of 47,XY,+21[1]/46,XY[39], 47,XY,+21[2]/46,XY[38] and 46,XY in 40/40 cells, respectively. When follow-up at age 1 year and 2 months, the neonate was normal in phenotype and development. The peripheral blood had a karyotype of 46,XY in 40/40 cells, and interphase FISH analysis on uncultured buccal mucosal cells showed 6.4% (7/109 cells) mosaicism for trisomy 21. 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 trisomy 21 cell line and a favorable fetal outcome.

Mosaic distal 9p deletion or 46,XY,del(9)(p23)/46,XY at amniocentesis in a pregnancy associated with perinatal progressive decrease of the aneuploid cell line and a favorable fetal outcome.

OBJECTIVE: We present mosaic distal 9p deletion at prenatal diagnosis in a pregnancy associated 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 46,XY, del(9)(p23)[8]/46,XY[17]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes showed 43% mosaicism for the 9p24.3p23 deletion. Prenatal ultrasound suspected hypospadias and echogenic bowel. At 23 weeks of gestation, she was referred for genetic counseling, and repeat amniocentesis revealed a karyotype of 46,XY,del(9)(p23)[10]/46,XY[10]. The parental karyotypes were normal. Molecular genetic analysis on uncultured amniocytes revealed no uniparental disomy (UPD) 9 by quantitative fluorescence polymerase chain reaction (QF-PCR) and arr 9p24.3p23 × 1.55 (40%-50% mosaicism) by aCGH. At 27 weeks of gestation, she underwent the third amniocentesis which revealed a karyotype of 46,XY,del(9)(p23)[6]/46,XY[14]. Simultaneous aCGH analysis on the DNA extracted from uncultured amniocytes revealed the result of arr 9p24.3p23 (35% mosaicism). Prenatal ultrasound was normal. She was advised to continue the pregnancy, and a 3020-g phenotypically normal male baby was delivered at 41 weeks of gestation. At birth, the karyotypes of cord blood, umbilical cord and placenta were 46,XY,del(9)(p23)[7]/46,XY[37], 46,XY,del(9)(p23)[17]/46,XY[23] and 46,XY in 40/40 cells, respectively. When follow-up at age three months, the neonate was normal in phenotype and development. The peripheral blood had a karyotype of 46,XY,del(9)(p23)[3]/46,XY[37], and interphase fluorescence in situ hybridization (FISH) analysis on buccal mucosal cells showed 13% (13/102 cells) mosaicism for the distal 9p deletion. CONCLUSION: Mosaic distal 9p deletion with a normal cell line at prenatal diagnosis can be associated with a favorable fetal outcome and perinatal progressive decrease of the aneuploid cell line.

Low-level mosaic trisomy 7 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.

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. CASE REPORT: 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. CONCLUSION: 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.

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.

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.

Mosaic distal 10q deletion or 46,XY,del(10) (q26.13)/46,XY at amniocentesis and cordocentesis 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 mosaic distal 10q deletion at prenatal diagnosis in a pregnancy associated with a favorable fetal outcome. CASE REPORT: A 40-year-old, gravida 2, para 0, woman underwent amniocentesis at 16 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY, del(10) (q26.13)[6]/46,XY[17]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes showed 35% mosaicism for the 10q26.13q26.3 deletion. At 22 weeks of gestation, she underwent cordocentesis which revealed a karyotype of 46,XY,del(10) (q26.13)[16]/46,XY[24]. Prenatal ultrasound findings were normal. At 24 weeks of gestation, she was referred for genetic counseling, and repeat amniocentesis revealed a karyotype of 46,XY,del(10) (q26.13)[4]/46,XY[22]. The parental karyotypes were normal. Molecular genetic analysis on uncultured amniocytes revealed no uniparental disomy (UPD) 10 by quantitative fluorescence polymerase chain reaction (QF-PCR), arr 10q26.13q26.3 × 1.6 (40% mosaicism) by aCGH, and 29.8% (31/104 cells) mosaicism for the distal 10q deletion by interphase fluorescence in situ hybridization (FISH). The woman was advised to continue the pregnancy, and a phenotypically normal 2,900-g male baby was delivered at 39 weeks of gestation. The cord blood had a karyotype of 46,XY,del(10) (q26.13)[6]/46,XY[34], and both the umbilical cord and the placenta had the karyotype of 46,XY. When follow-up at age four months, the neonate was normal in phenotype and development. The peripheral blood had a karyotype of 46,XY,del(10) (q26.13)[5]/46,XY[35], and interphase FISH analysis on buccal mucosal cells showed 8% (8/102 cells) mosaicism for distal 10q deletion. CONCLUSION: Mosaic distal 10q deletion with a normal cell line at prenatal diagnosis can be associated with a favorable fetal outcome and perinatal progressive decrease of the aneuploid cell line.

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.

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 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.

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.

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.

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.