Rapid detection of K650E mutation in FGFR3 using uncultured amniocytes in a pregnancy affected with fetal cloverleaf skull,occipital pseudoencephalocele,ventriculomegaly, straight short femurs,and thanatophoric dysplasia type II

ObjectiveTo present the ultrasound and molecular genetic diagnosis of thanatophoric dysplasia type II (TD2).Case ReportA 35-year-old, primigravid woman was referred to our institution for genetic counseling and amniocentesis at 19 weeks of gestation because of advanced maternal age and sonographic abnormalities in the fetus. The prenatal ultrasound showed short straight femurs, prominent forehead, narrow chest, skin edema, short limbs, and cloverleaf skull consistent with the diagnosis of TD2. Amniocentesis revealed a karyotype of 46,XX. DNA testing for the FGFR3 gene using uncultured amniocytes revealed a heterozygous c.1948A>G, AAG>GAG transversion leading to a p.Lys650Glu(K650E) mutation in the FGFR3 gene. A prenatal ultrasound at 21 weeks of gestation showed ventriculomegaly, cloverleaf skull, straight femurs, micromelia, narrow chest, and pseudoencephalocele with a bulging occipital bone mimicking encephalocele. The pregnancy was subsequently terminated, and a 480-g malformed fetus was delivered with macrocephaly, depressed nasal bridge, short upturned nasal tip, hypoplastic midface, frontal bossing, short digits, trident-shaped hands, short limbs, cloverleaf skull, narrow chest, brachydactyly, nuchal edema, and bulging occipital bone.ConclusionA prenatal diagnosis of cloverleaf skull, short limbs, straight femurs, and occipital pseudoencephalocele should include a differential diagnosis of TD2. A molecular analysis of FGFR3 using uncultured amniocytes is useful for the rapid confirmation of TD2 at prenatal diagnosis.     

Progressive development of sonographic features in prenatal diagnosis of Apert syndrome--case report and literature review

Apert syndrome is characterized by craniosynostosis, midfacial malformations and symmetrical syndactyly of the hands and feet. We report a case of prenatal sonographic diagnosis of Apert syndrome. Mild ventriculomegaly with normal head shape observed at 22 weeks gestation, followed by colpocephaly at 25 weeks gestation and bilateral syndactyly and subsequent craniosynostosis at 28 weeks, led to the prenatal diagnosis of Apert syndrome. The diagnosis was confirmed by physical examination and molecular study after birth. Additionally the authors present the review of literature on prenatal sonographic diagnosis of Apert syndrome.     

Prenatal diagnosis and molecular cytogenetic characterization of a 1.07-Mb microdeletion at 5q35.2–q35.3 associated with NSD1 haploinsufficiency and Sotos syndrome

ObjectiveTo present prenatal diagnosis and molecular cytogenetic characterization of a de novo 5q35 microdeletion associated with Sotos syndrome.MethodsThis was the first pregnancy of a 29-year-old woman. The pregnancy was uneventful until 27 weeks of gestation when left ventriculomegaly was first noted. At 31 weeks of gestation, polyhydramnios, macrocephaly, and ventriculomegaly were prominent on ultrasound, and left pyelectasis and bilateral ventriculomegaly were diagnosed on magnetic resonance imaging. The woman underwent amniocentesis and cordocentesis at 32 weeks of gestation. Conventional cytogenetic analysis was performed using cultured amniocytes and cord blood lymphocytes. Array comparative genomic hybridization (aCGH) was performed on uncultured amniocytes and parental blood. Metaphase fluorescence in situ hybridization (FISH) was performed on cultured lymphocytes.ResultsConventional cytogenetics revealed a karyotype of 46,XX. aCGH on uncultured amniocytes revealed a de novo 1.07-Mb microdeletion at 5q35.2–q35.3 encompassing NSD1. Metaphase FISH analysis on the cord blood lymphocytes confirmed the deletion at 5q35.2. The postnatal phenotype was consistent with Sotos syndrome.ConclusionFetuses with Sotos syndrome may present macrocephaly, polyhydramnios, ventriculomegaly, and pyelectasis in the third trimester. aCGH and metaphase FISH are useful for rapid diagnosis of 5q35 microdeletion associated with Sotos syndrome.     

A de novo duplication of chromosome 21q22.11→qter associated with Down syndrome: prenatal diagnosis, molecular cytogenetic characterization and fetal ultrasound findings

ObjectivesTo present prenatal diagnosis and molecular cytogenetic characterization of de novo partial partial trisomy 21q (21q22.11 → qter) associated with clinodactyly and hypoplastic midphalanx of the fifth fingers, midface hypoplasia, and an intracardiac echogenic focus on prenatal ultrasound.Materials, Methods, and ResultsA 34-year-old gravida 2, para 1 woman underwent amniocentesis at 20 weeks of gestation because of fetal structural abnormalities on prenatal ultrasound. A level II ultrasound at 20 weeks of gestation showed polyhydramnios, clinodactyly and hypoplastic midphalanx of the fifth fingers, midface hypoplasia, and an intracardiac echogenic focus. Amniocentesis revealed an aberrant derivative chromosome 9, or der(9). Parental karyotypes were normal. Spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) analyses revealed that the der(9) contained a segment of chromosome 21 distal to chromosome 9q, and FISH analysis additionally showed that the distal subtelomeric region of 9q was not deleted. Array comparative genomic hybridization (aCGH) demonstrated a 14.8-Mb duplication of distal 21q encompassing the Down syndrome critical region (DSCR) but no genomic imbalance in the distal euchromatic region of chromosome 9. The karyotype was 46,XX,der(9)t(9;21) (q34.3;q22.11)dn. Polymorphic DNA marker analysis revealed the maternal origin of the aberrant chromosome. The pregnancy was subsequently terminated. A malformed female fetus was delivered with a characteristic phenotype of Down syndrome.ConclusionSKY, FISH and aCGH are useful in prenatal investigation of the nature of a de novo aberrant derivative chromosome. Partial trisomy 21q encompassing the DSCR may present characteristic Down syndrome features on prenatal ultrasound.     

Prenatal diagnosis of maternal uniparental disomy 16 associated with mosaic trisomy 16 at amniocentesis,and pericardial effusion and intrauterine growth restriction in the fetus

ObjectiveWe present prenatal diagnosis of maternal uniparental disomy (UPD) 16 associated with mosaic trisomy 16 at amniocentesis, and pericardial effusion and intrauterine growth restriction (IUGR) in the fetus.Case reportA 38-year-old woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age, and the result was 47,XX,+16[2]/46,XX[54]. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed 14% mosaicism for trisomy 16 and a paternally inherited 319-kb microdeletion of 15q11.2 encompassing the genes of TUBGCP5, CYFIP1, NIPA2 and NIPA1. Prenatal ultrasound revealed persistent left superior vena cava, pericardial effusion and severe IUGR. Cordocentesis at 23 weeks of gestation revealed a karyotype of 46,XX, but polymorphic DNA marker analysis revealed maternal UPD 16. Repeat amniocentesis was performed at 27 weeks of gestation and revealed a karyotype of 46, XX in 21/21 colonies. Molecular cytogenetic analysis on uncultured amniocytes revealed 22.4% mosaicism (26/116 cells) for trisomy 16 on interphase fluorescence in situ hybridization (FISH) analysis, and 20% mosaicism for trisomy 16 on aCGH. Polymorphic DNA marker analysis on the DNAs extracted from uncultured amniocytes and parental bloods revealed maternal UPD 16. The pregnancy was subsequently terminated, and a fetus was delivered with facial dysmorphism and severe IUGR. The umbilical cord had a karyotype of 47,XX,+16[28]/46,XX[16]. Polymorphic DNA marker analysis on placenta confirmed a maternal origin of trisomy 16.ConclusionCytogenetic discrepancy between cultured amniocytes and uncultured amniocytes may present in mosaic trisomy 16 at amniocentesis. Prenatal diagnosis of mosaic trisomy 16 should alert the association of maternal UPD 16 which may be associated with congenital heart defects and severe IUGR on prenatal ultrasound.     

Prenatal diagnosis of hydrancephaly and enlarged cerebellum and cisterna magna in a fetus with thanatophoric dysplasia type II and a review of prenatal diagnosis of brain anomalies associated with thanatophoric dysplasia

Objective

We present prenatal diagnosis of hydrancephaly and enlarged cerebellum and cisterna magna in a fetus with thanatophoric dysplasia type II (TD2) and a review of prenatal diagnosis of brain anomalies associated with TD.

Wolf–Hirschhorn syndrome: Prenatal diagnosis and molecular cytogenetic characterization of a de novo distal deletion of 4p (4p16.1 → pter) in a fetus with facial cleft and preaxial polydactyly

ObjectiveWe present prenatal diagnosis and molecular cytogenetic characterization of Wolf–Hirschhorn syndrome (WHS) in a fetus with facial cleft and preaxial polydactyly.Materials and methodsA 37-year-old woman underwent amniocentesis at 18 weeks of gestation because of advanced maternal age, and the result showed an aberrant chromosome 4 or 46,XX,add(4) (p15.3). The woman consulted our clinics at 22 weeks of gestation and requested for repeat amniocentesis. Prenatal ultrasound revealed intrauterine growth restriction, facial cleft, vermian hypoplasia of cerebellum, micrognathia and absent stomach. Conventional cytogenetic analysis was performed on cultured amniocytes, parental bloods and cord blood. Array comparative genomic hybridization (aCGH) and quantitative fluorescent polymerase chain reaction (QF-PCR) were performed on the DNAs extracted from uncultured amniocytes and parental bloods. Fluorescence in situ hybridization (FISH) analysis was performed on cultured metaphase amniocytes.ResultsaCGH analysis on uncultured amniocytes revealed arr 4p16.3p16.1 (74,447–8,732,731) × 1.0 [GRCh37 (hg19)] with an 8.66-Mb deletion of 4p16.3-p16.1 encompassing 70 [Online Mendelian Inheritance of in Man (OMIM)] genes including ZNF141, FGFRL1, TACC3, LETM1, NSD2 and NELFA. QF-PCR revealed a paternal origin of the distal 4p deletion. Conventional cytogenetic analysis revealed 46,XX,del(4) (p16.1)dn in the fetus. Metaphase FISH analysis confirmed a 4p16 deletion. The parental karyotypes were normal. The pregnancy was subsequently terminated, and a malformed fetus was delivered with typical WHS facial dysmorphism, bilateral cleft lip and palate, and preaxial polydactyly on the right hand.ConclusionaCGH, QF-PCR and FISH help to delineate the nature of a prenatally defected aberrant chromosome, and the acquired information is useful for genetic counseling.     

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

ObjectiveWe 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 reportA 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.ConclusionMosaic 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.     

Prenatal diagnosis of sporadic Apert syndrome: a sequential diagnostic approach combining three-dimensional computed tomography and molecular biology

Apert syndrome is characterized by coronal craniosynostosis, midfacial hypoplasia, symmetrical syndactyly of the hands and feet described as 'mitten-like' with varying degrees of mental retardation. It results from a mutation of the fibroblast growth factor-2 (FGFR2) gene. In the absence of a family history, prenatal diagnosis may be difficult based on sonography alone. We report a case in which the prenatal diagnosis of Apert syndrome was suspected by ultrasonography, established by three-dimensional computed tomography scan (3DTS) and confirmed by the detection of a mutation on amniotic cells. This underscores the usefulness of a sequential diagnostic approach combining 3DTS and molecular biology in cases in which sonography alone is not con- clusive.     

Detection of hypermethylation at H19DMR at amniocentesis in a fetus with overgrowth,distended abdomen and Beckwith-Wiedemann syndrome

ObjectiveWe present detection of hypermethylation at H19 differentially methylated region (DMR) at amniocentesis in a fetus with overgrowth, distended abdomen and Beckwith-Wiedemann syndrome (BWS).Case reportA 31-year-old, gravida 2, para 1, woman was referred for genetic counseling at 22 weeks of gestation because of fetal overgrowth with fetal biometry equivalent to 24 weeks of gestation and a distended abdomen with an abdominal circumference equivalent to 26 weeks of gestation. She did not undergo any assisted reproductive technology during this pregnancy. Amniocentesis was performed at 23 weeks of gestation. Conventional cytogenetic analysis revealed a karyotype of 46,XX. Array comparative genomic hybridization analysis on the DNA extracted from uncultured amniocytes revealed no genomic imbalance. Methylation analysis on the DNA extracted from amniocytes revealed hypermethylation at H19DMR [imprinting center 1 (IC1)] and normal methylation at KvDMR1 (IC2). The methylation test confirmed the diagnosis of BWS in the fetus. The parents decided to continue the pregnancy. At 36 weeks of gestation, a 4000-g female baby was delivered with macroglossia, ear tags and creases, and an enlarged liver, consistent with the phenotype of BWS.ConclusionPrenatal diagnosis of fetal overgrowth should include a differential diagnosis of BWS, and methylation analysis of H19DMR (IC1) and KvDMR1 (IC2) is useful under such a circumstance.     

Rapid positive confirmation of mosaicism for a small supernumerary marker chromosome as r(8) by interphase fluorescence in situ hybridization,quantitative fluorescent polymerase chain reaction,and array comparative genomic hybridization on uncultured amniocytes in a pregnancy with fetal pyelectasis

ObjectiveThis study aimed at presenting prenatal diagnosis and molecular cytogenetic characterization of a small supernumerary marker chromosome (sSMC) derived from chromosome 8 by fluorescence in situ hybridization (FISH), quantitative fluorescent polymerase chain reaction (QF-PCR), and array comparative genomic hybridization (aCGH) on uncultured amniocytes.Materials, Methods, and ResultsA 32-year-old woman underwent amniocentesis at 19 weeks of gestation because of fetal pyelectasis. Amniocentesis revealed a de novo ring-shaped sSMC in two of 21 colonies of cultured amniocytes. Repeated amniocentesis at 22 weeks of gestation revealed a karyotype of 47,XY,+mar[8]/46,XY[32] in cultured amniocytes. Spectral karyotyping and FISH confirmed that the sSMC was derived from chromosome 8. She underwent a third amniocentesis at 26 weeks of gestation. Oligonucleotide-based aCGH analysis on uncultured amniocytes demonstrated a 43 Mb genomic gain in chromosome 8 encompassing 8p22→q12.1. Polymorphic DNA marker analysis of the uncultured amniocytes revealed a maternal origin of the sSMC and excluded uniparental disomy 8. Interphase FISH analysis showed three D8Z2 signals in 8/40 (20%) of uncultured amniocytes. The cultured amniocytes had a karyotype of 47,XY,+r(8)(p22q12.1)[3]/46,XY[37]. The pregnancy was carried to term, and an apparently normal baby, weighing 3300 g, was delivered with mild hydronephrosis but no other phenotypic abnormalities. The cord blood was found to have a karyotype of 47,XY,+r(8)(p22q12.1)[2]/46,XY[38].ConclusionPrenatal diagnosis of fetal pyelectasis should alert obstetricians of chromosome aberration. Interphase FISH, QF-PCR, and aCGH analyses on uncultured amniocytes are helpful in rapid positive confirmation of an sSMC detected at amniocentesis.     

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

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

Rapid diagnosis of trisomy 13 of maternal origin by quantitative fluorescent polymerase chain reaction analysis in a pregnancy with fetal holoprosencephaly,premaxillary agenesis,postaxial polydactyly of left hand and overriding aorta

ObjectiveWe present rapid diagnosis of trisomy 13 of maternal origin by quantitative fluorescent polymerase chain reaction (QF-PCR) in a pregnancy with multiple fetal abnormalities.Case reportA 35-year-old, primigravid woman was referred for amniocentesis at 24 weeks of gestation because of multiple congenital anomalies in the fetus. Prenatal ultrasound at 23 weeks of gestation revealed holoprosencephaly, premaxillary agenesis, postaxial polydactyly of the left hand and overriding aorta. Amniocentesis was performed subsequently, and QF-PCR analysis using the polymorphic DNA markers of D13S789 (13q22.3), D13S790 (13q31.1) and D13S767 (13q31.3) on the DNA extracted from uncultured amniocytes and parental bloods showed trisomy 13 of maternal origin. Conventional cytogenetic analysis on the cultured amniocytes confirmed trisomy 13. The pregnancy was subsequently terminated, and a malformed fetus was delivered with multiple anomalies consistent with the prenatal diagnosis.ConclusionQF-PCR analysis is useful for rapid confirmation of trisomy 13 and the parental origin when prenatal ultrasound findings are suspicious of fetal trisomy 13.     

Application of the three-dimensional maximum mode in prenatal diagnosis of Apert syndrome

Apert syndrome is a rare disorder characterized by coronal craniosynostosis, syndactyly, brachycephaly, midfacial hypoplasia, and central nervous system anomalies, among other malformations. We present a case of Apert syndrome examined at 22 + 0 weeks' gestation. Three-dimensional maximum mode was decisive for the correct prenatal diagnosis by demonstrating the cranial deformities.     

Mosaic isochromosome 20q at amniocentesis: Prenatal diagnosis,genetic counseling and literature review

ObjectiveWe present prenatal diagnosis of mosaic isochromosome 20q [i(20q)] at amniocentesis, and we review the literature.Case reportA 36-year-old woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY,i(20)(q10)[27]/46,XY[29]. Prenatal ultrasound findings were unremarkable. The parental karyotypes were normal. Repeat amniocentesis was performed at 20 weeks of gestation. During repeat amniocentesis, array comparative genomic hybridization (aCGH), interphase fluorescence in situ hybridization (FISH) and quantitative fluorescent polymerase chain reaction (QF-PCR) assay were performed on uncultured amniocytes, and conventional cytogenetic analysis, interphase FISH and aCGH were performed on cultured amniocytes. In the repeat amniocentesis, the cultured amniocytes revealed a karyotype of 46,XY. Interphase FISH analysis showed the i(20q) signal in 5.2% (5/96) of the uncultured amniocytes compared with 2% in the control, and in 0.98% (1/102) of the cultured amniocytes compared with 2% in the control. aCGH detected no genomic imbalance in both uncultured and cultured amniocytes. QF-PCR analysis excluded uniparental disomy 20. At 38 weeks of gestation, a healthy 2870-g male baby was delivered with no phenotypic abnormality. The postnatal blood karyotype was 46,XY. FISH analysis on urinary cells showed 2.1% (2/95 cells) mosaicism compared with 1.9% (2/105 cells) in the control.ConclusionMosaic i(20q) at amniocentesis is a benign condition associated with a favorable outcome in most cases and can be a cell culture artifact confined to cultured amniocytes. Molecular cytogenetic analysis using uncultured amniocytes is useful for rapid confirmation. Prenatal diagnosis of very high percentage of mosaicism for i(20q) at amniocentesis should alert the presence of fetal structural abnormalities. Prenatal diagnosis of mosaic i(20q) at amniocentesis should include a detail examination of fetal brain and spine.     

Prenatal diagnosis of familial 22q11.2 deletion syndrome in a pregnancy with concomitant cardiac and urinary tract abnormalities in the fetus and the mother

ObjectiveWe present prenatal diagnosis of familial 22q11.2 deletion syndrome in a pregnancy with concomitant cardiac and urinary tract abnormalities in the fetus and the mother.Case reportA 28-year-old woman primigravid underwent amniocentesis at 23 weeks of gestation because of fetal ultrasound findings of aortic stenosis, interrupted aortic arch (IAA), left multicystic kidney, right hydronephrosis and ureterocele. Amniocentesis revealed a karyotype of 46,XX. Simultaneous array comparative genomic hybridization (aCGH) analysis on the DNA extracted from uncultured amniocytes revealed the result of arr 22q11.21 (18,894,835-21,505,417) × 1.0 [GRCh37 (hg19)] with a 2.611-Mb 22q11.21 deletion encompassing 41 Online Mendelian Inheritance in Man (OMIM) genes including UFD1L, TBX1, GNB1L, COMT and MED15. aCGH analysis on the DNAs extracted from parental bloods confirmed that the mother carried the same 22q11.21 microdeletion. Level II ultrasound additionally found ventricular septal defect (VSD) and persistent left superior vena cava (PLSVC). Examination of the woman showed short stature, malar hypoplasia, hypertelorism, bulbous nasal tip, prominent nasal root, hypoplasia of nasal wings, right renal agenesis, left ureterovesical reflux and VSD with repair, but normal intelligence and normal neuropsychiatric development. The woman decided to continue the pregnancy, and a 2903-g female baby was delivered at 38 weeks of gestation with left multicystic kidney, right hydronephrosis, dysgenesis of corpus callosum, IAA, VSD, PLSVC, patent ductus arteriosus, patent foramen ovale, atrial septal defect, dilated main pulmonary artery and tricuspid regurgitation. The neonate died at the age of one month.ConclusionPrenatal diagnosis of concomitant congenital heart defects and urinary tract abnormalities in the fetus and the parent should raise a suspicion of familial 22q11.2 deletion syndrome.     

Trisomy 7 mosaicism at amniocentesis: interphase FISH, QF-PCR, and aCGH analyses on uncultured amniocytes for rapid distinguishing of true mosaicism from pseudomosaicism

ObjectiveTo present prenatal diagnosis of true trisomy 7 mosaicism.Materials, Methods and ResultsA 36-year-old woman underwent amniocentesis at 18 weeks of gestation. Amniocentesis revealed a karyotype of 47,XY,+7[20]/46,XY[9]. The parental karyotypes were normal. Repeated amniocentesis was performed at 20 weeks of gestation. Array comparative genomic hybridization (aCGH) analysis on uncultured amniocytes manifested a genomic gain in chromosome 7. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on uncultured amniocytes showed a biparental diallelic pattern with a dosage increase in the maternal allele. Interphase fluorescence in situ hybridization (FISH) on uncultured amniocytes revealed three 7q-specific signals in 13 of 50 (26%) of the cells. The cultured amniocytes had a karyotype of 47,XY,+7[12]/46,XY[14]. The ultrasound findings were unremarkable. The pregnancy was subsequently terminated, and a fetus was delivered with facial dysmorphisms. Postnatal tissue samplings revealed the mosaic trisomy 7 level of 37.5% (15/40), 30% (12/40), 42.5% (17/40), 82.5% (33/40), 52.5% (21/40), and 27.5% (11/40) in skin, liver, lungs, placenta, membrane, and cord, respectively. The cord blood had a karyotype of 46,XY. PEG1/MEST methylation-sensitive high-resolution melting PCR assay of cord blood showed no uniparental disomy for chromosome 7.ConclusionInterphase FISH, QF-PCR, and aCGH analyses on uncultured amniocytes are useful for rapid distinguishing of true mosaicism from pseudomosaicism for trisomy 7 at amniocentesis. Cord blood sampling for confirmation of fetal trisomy 7 mosaicism is not practical.     

Prenatal diagnosis and molecular cytogenetic characterization of mosaicism for a small supernumerary marker chromosome derived from 2q11.1-q12.1 associated with fetal bilateral radial dysplasia

ObjectiveWe present prenatal diagnosis and molecular cytogenetic characterization of mosaicism for a small supernumerary marker chromosome (sSMC) derived from 2q11.1-q12.1 associated with fetal bilateral radial dysplasia.Case reportA 27-year-old woman underwent amniocentesis at 18 weeks of gestation because of club hands on fetal ultrasound. The internal organs of the fetus were normal. Amniocentesis revealed a karyotype of 47,XY,+mar [13]/46,XY [11]. The parental karyotypes were normal. Simultaneous array comparative genomic hybridization (aCGH) analysis of the DNA extracted from uncultured amniocytes revealed the result of arr 2q11.1q12.1 (95,529,039–102,825,556) × 3.0 [GRCh37 (hg19)]. The pregnancy was terminated at 20 weeks of gestation, and a malformed fetus was delivered with isolated bilateral radial dysplasia. The cord blood had a karyotype of 47,XY,+mar[24]/46,XY[16]. Polymorphic DNA marker analysis of the DNAs extracted from umbilical cord and parental bloods excluded uniparental disomy for chromosome 2. Metaphase fluorescence in situ hybridization analysis confirmed an sSMC derived from chromosome 2q11.1-q12.1 in cultured amniocytes.ConclusionHigh-level mosaicism for an sSMC derived from chromosome 2q11.1-q12.1 can be associated with fetal abnormalities.     

Contribution of tridimensional sonography and magnetic resonance imaging to prenatal diagnosis of Apert syndrome at mid-trimester

A diagnosis of Apert syndrome, suspected at 24 weeks' gestation after conventional sonography showing turribrachycephaly and syndactyly of hands and feet, was confirmed at 26 weeks' gestation by tridimensional sonography and magnetic resonance imaging. This is only the second prenatal diagnosis reported at mid-trimester, excluding cases published from affected mothers or in connection with a context of recurrence. Additional findings have been collected from tridimensional sonography (mid-facial hypoplasia, downslanting palpebral fissures) and from magnetic resonance imaging (verticalization of the clivus and flattened angle of the cranial base).     

Prenatal diagnosis of mosaicism for trisomy 11 in a single colony at amniocentesis in a pregnancy with a favorable outcome

ObjectiveWe present prenatal diagnosis of mosaicism for trisomy 11 in a single colony at amniocentesis with a favorable outcome.Case ReportA 34-year-old woman underwent amniocentesis at 16 weeks of gestation because of advanced maternal age. Amniocentesis revealed a result of 47,XY,+11[1]/46,XY[9]. In 10 colonies of cultured amniocytes, all five cells in one colony had a karyotype of trisomy 11, while the rest nine colonies had a normal karyotype. The parental karyotypes were normal. Repeat amniocentesis was performed at 19 weeks of gestation. Interphase fluorescence in situ hybridization (FISH) was applied on the uncultured amniocytes, and the result showed no trisomy 11 signals in 56/56 uncultured amniocytes. Uniparental disomy (UPD) 11 was excluded by polymorphic DNA marker analysis. The cultured amniocytes at repeat amniocentesis had a karyotype of 46,XY. Prenatal ultrasound findings were unremarkable. A healthy 3084-g male baby was delivered at 38 weeks of gestation. The karyotype of cord blood lymphocytes was 46,XY. The boy was phenotypically normal at age 10 months at follow-ups. The interphase FISH analysis on urinary cells revealed no trisomy 11 signal.ConclusionMosaicism for trisomy 11 in a single colony at amniocentesis without UPD 11 can be associated with a favorable outcome.