Identification of a critical region on chromosome 4p16.3 for Wolf-Hirschhorn syndrome-associated fetal growth retardation / 中华医学遗传学杂志

OBJECTIVE@#To analyze ultrasonographic finding in fetuses with Wolf-Hirschhorn syndrome (WHS) and refine the critical region on chromosome 4p16.3 for WHS-associated fetal growth retardation (FGR).@*METHODS@#In total 2262 fetuses with abnormal ultrasonographic findings who underwent prenatal karyotyping and chromosomal microarray analysis were reviewed. WHS-associated 4p deletions detected in these fetuses were compared, and prenatal ultrasound findings in such fetuses were summarized. Meanwhile, WHS cases with prenatal ultrasound findings and isolated 4p deletions in previous studies were included for further analysis. An analysis of smallest region of overlap (SRO) among discrepant 4p deletions in these cases above was performed to define a critical region for FGR.@*RESULTS@#4p deletions were detected in 10 of the 2262 fetuses and 5.0% of the 202 fetuses with FGR. Combined with 80 WHS cases from previous studies, the most common prenatal ultrasound finding was FGR, which yielded a frequency of 76.7%. In addition, a SRO spanning approximately 419 kb (genomic position: 1.32-1.74 Mb) on chromosome 4p16.3 was discovered by comparing the unusual 4p deletions among the 10 fetuses. The region contained seven protein-coding genes, including TACC3, SLBP, TMEM129, FAM53A, MAEA, UVSSA and CRIPAK.@*CONCLUSION@#For fetuses with WHS, the most common prenatal ultrasound phenotype was FGR. A region between 1.32 Mb to 1.74 Mb from the telomere on chromosome 4p16.3 is critical for WHS-associated FGR, for which TACC3 and SLBP are the candidate genes.

Prenatal genetic analysis of two fetuses with Miller-Dieker syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To perform molecular cytogenetic study on two fetuses with abnormal ultrasound findings and analyze their genotype-phenotype correlation.</p><p><b>METHODS</b>G-banded karyotyping, single nucleotide polymorphism array (SNP array) and fluorescence in situ hybridization (FISH) were performed on amniotic fluid cells from both fetuses and peripheral blood samples from their parents. Results of SNP array were analyzed with bioinformatics software.</p><p><b>RESULTS</b>G-banded karyotyping failed to detect any abnormalities in both fetuses and their parents. SNP array detected a 2.484 Mb terminal deletion at 17p13.3 [arr[hg19] 17p13.3 (83 035-2 567 405)×1] in fetus 1 and a 3.295 Mb terminal deletion at 17p13.3p13.2 [arr[hg19] 17p13.3p13.2 (83 035- 3 377 560)×1] in fetus 2. Both deletions have overlapped with the critical region of Miller-Dieker syndrome (MDS) and involved candidate genes such as PAFAH1B1, YWHAE and CRK. In addition, SNP array and FISH analyses on the parental peripheral blood samples demonstrated that both 17p13.3 and 17p13.3p13.2 deletions were of de novo origin. Metaphase FISH performed on amniotic fluid cells confirmed the presence of 17p13.3 and 17p13.3p13.2 deletions detected by the SNP array, while metaphase FISH performed on the parents excluded any potential chromosome rearrangements.</p><p><b>CONCLUSION</b>Abnormal ultrasound features for fetuses with MDS mainly include central nervous system anomalies. SNP array can efficiently detect 17p13.3 microdeletions underlying MDS, and accurately map the breakpoints and involved genes, which may facilitate understanding of the genotype and phenotype correlations for MDS.</p>

Prenatal genetic diagnosis for a fetus with atypical neurofibromatosis type 1 microdeletion / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the correlation between atypical neurofibromatosis type 1(NF1) microdeletion and fetal phenotype.</p><p><b>METHODS</b>Fetal blood sampling was carried out for a woman bearing a fetus with talipes equinovarus. G-banded karyotyping and single nucleotide polymorphism array (SNP-array) were performed on the fetal blood sample. Fluorescence in situ hybridization (FISH) was used to confirm the result of SNP array analysis. FISH assay was also carried out on peripheral blood specimens from the parents to ascertain the origin of mutation.</p><p><b>RESULTS</b>The karyotype of fetus was found to be 46, XY by G-banding analysis. However, a 3.132 Mb microdeletion was detected in chromosome region 17q11.2 by SNP array, which overlaped with the region of NF1 microdeletion syndrome. Analyzing of the specimens from the fetus and its parents with FISH has confirmed it to be a de novo deletion.</p><p><b>CONCLUSION</b>Talipes equinovarus may be an abnormal sonographic feature of fetus with atypical NF1 microdeletion which can be accurately diagnosed with SNP array.</p>

Genetic analysis of a fetus with partial 1q monosomy and partial 17q trisomy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze a fetus with abnormal sonographic features and correlated its genotype with phenotype.</p><p><b>METHODS</b>G-banding analysis, single nucleotide polymorphism array (SNP array) and fluorescence in situ hybridization (FISH) were performed for the fetus. Karyotyping and FISH were also carried out for the parents.</p><p><b>RESULTS</b>SNP array detected a 4.4 Mb deletion at 1q44 and a 10.4 Mb duplication at 17q24.3q25.3 in the fetus. Based on the results of SNP array and FISH analysis, the father was diagnosed with a cryptic t(1;17)(q44;q24.3) translocation. The fetus has inherited a der(1)t(1;17)(q44;q24.3) from its father.</p><p><b>CONCLUSION</b>The 1q44 deletion and 17q24.3q25.3 duplication may have contributed to the abnormal sonographic features presented by the fetus.</p>

Prenatal diagnosis of 1p36.3 microdeletion in a fetus with complex heart defect / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze a fetus presenting with complex heart defect and assess the recurrence risk.</p><p><b>METHODS</b>Conventional karyotyping, fluorescence in situ hybridization (FISH) and single nucleotide polymorphism-based array (SNP-array) were used to analyze the fetus and his parents.</p><p><b>RESULTS</b>SNP-array has detected a 6.9 Mb microdeletion at 1p36.33-p36.23 in the fetus. Chromosomal and FISH analyses indicated that the father of the fetus had a karyotype of 46,XY,t(1;14)(p36.3;p12), and that the fetus has inherited an abnormal chromosome 1 derived from the paternal translocation.</p><p><b>CONCLUSION</b>SNP-array combined with GTG banding and FISH can help to detect cryptic translocation, microdeletion or microduplication of chromosomes and is valuable to assess the recurrence risk for the affected family.</p>

Application of single nucleotide polymorphism-based array analysis for prenatal diagnosis of a fetus with de novo derivative chromosome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze a fetus with increased nuchal translucency and nuchal fold, and to assess the recurrence risk for her family and provide a basis for prenatal diagnosis.</p><p><b>METHODS</b>G-banded karyotyping and single nucleotide polymorphism-based array (SNP-Array) analysis were used to analyze the fetus and her parents.</p><p><b>RESULTS</b>SNP-Array analysis has detected a 41.04 Mb duplication at Xp22.33p11.4 and a 30.51 Mb duplication at 13q31.3q34 in the fetus. G-banding karyotyping indicated that the fetus had a karyotype of 46,X,der(X)(13qter-13q31::Xp11.4-Xp22.3::Xp22.3-Xqter). Her parents had normal results for both G-banding karyotyping and SNP-Array analysis, suggesting that the fetus has carried a de novo derivative chromosome X.</p><p><b>CONCLUSION</b>SNP-Array combined with G-banding karyotyping is helpful to confirm the composition and connection type of de novo derivative chromosome, which can improve the accuracy of diagnosis and is valuable for the evaluation of recurrence risk.</p>

Prenatal diagnosis of five cases of monochorionic-diamniotic twins discordant for karyotype analysis / 中华医学遗传学杂志

OBJECTIVE To explore the mechanism and diagnostic method for monochorionic-diamniotic twins discordant for karyotype analysis. METHODS Dual amniocentesis was performed on five pairs of monochorionic-diamniotic twins, which all consisted of a normal twin and one with multiple malformations revealed by ultrasound. Karyotype analysis was performed on amniocytes derived from each of the twins. Zygosity was also determined with DNA extracted from amniocytes with 16 polymorphic microsatellite markers. RESULTS Three cases of 45,X, one case of 47,XX,+9 and one case of 47,XY,+18 were detected among the abnormal twins, while the normal fetuses all had a normal karyotype. DNA analysis suggested that, in all cases, the twins have shared the 16 polymorphic microsatellite markers, which confirmed their monozygosity. CONCLUSION Monochorionic-diamniotic twins may be discordant for karyotyping, for which anaphase lagging, chromosomal non-disjunction and trisomy rescue may be the underlying reasons. As a simple method, dual amniocentesis can be used to obtain amniotic fluid samples for karyotype analysis and determination of zygosity for such twins.

Chromosomal microarray analysis for lateral ventriculomegaly in fetus / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the relationship between fetal lateral ventriculomegaly and chromosomal microarray analysis (CMA) abnormalities.</p><p><b>METHODS</b>Fifty fetuses with lateral ventriculomegaly detected by ultrasound and a normal karyotype were included. Forty four fetuses were classified as mild ventriculomegaly (MVM), in which the lateral ventricular atrium was 10-15 mm. Six had severe ventriculomegaly (SVM), with the lateral ventricularatrium being ≥ 15 mm. The fetuses were also divided into isolated (n= 21) and non-isolated groups (n= 29) based on whether they are associated with other anomalies.</p><p><b>RESULTS</b>Thirteen (26%) of the fetuses were found to be abnormal by CMA. For the 44 cases with MVM, 9 (20.9% ) were found to be abnormal, while for the 6 cases with SMV, 4 (66.7%) were found to be abnormal (P>0.05). CMA abnormalities were found in 2 (9.5%) of the 21 fetuses with isolated ventriculomegaly group and 11 (37.9%) of the 29 fetuses with non-isolated ventriculomegaly group (P<0.05).</p><p><b>CONCLUSION</b>Chromosome microdeletions and microduplications are the most common abnormalities found in fetal lateral ventriculomegaly. When ventriculomegaly is associated with other anomalies, the incidence of CMA abnormally is much higher. Prenatal diagnosis is necessary for fetuses with lateral ventriculomegaly.</p>

Misdiagnosis of mosaic tetrasomy 9p in a fetus by single nucleotide polymorphism-based array / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the reason for discordant results of karyotyping and microarray analysis in a fetus with mosaic tetrasomy 9p.</p><p><b>METHODS</b>Amniocentesis was carried out for a pregnant woman with advanced age for whom ultrasound scan has indicated fetal ventricular expansion, intrauterine growth retardation and persistent upper venous cavity. G-banded karyotyping and single nucleotide polymorphism-based arrays (SNP-array) analysis were performed at the same time.</p><p><b>RESULTS</b>Analysis of amniocytic chromosome has suggested mosaic tetrasomy 9p (47,XX,+psu idic(9)(q21)[23]/46,XX[27]). While SNP-array has detected a non-mosaic trisomy 9p with a 68.7 Mb duplication at 9p24.3q21.11. The results of the two methods were therefore discordant.</p><p><b>CONCLUSION</b>SNP-array will analyze genetic material in the form of numbers rather than morphology. For chimeras containing two types of cell lines, when the mosaic rate was close to 50% and the average amount of genetic material of the chimeras was equivalent to the amount of genetic material of non-chimeras, microarray analysis may come to the conclusion of a non-mosaic heteroploidy. Therefore, microarray results for large segment chromosome abnormalities should be combined with the results of G-banded karyotyping for genetic counseling.</p>

Confirmation of a maternal cryptal balanced translocation through analysis of a fetus using microarray / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze a fetus with heart defects and to assess the recurrence risk for her family.</p><p><b>METHODS</b>Single nucleotide polymorphism-based arrays (SNP-Array) analysis using Affymetrix Genome Wide Human SNP CytoHD was performed to analyze the fetus and her parents. Karyotype analysis was also carried out.</p><p><b>RESULTS</b>SNP-Array has detected a 14.5 Mb duplication at 9p and a 14.7 Mb deletion at 11q. Karyotype analysis indicated that the fetus' mother has a karyotype of 46, XX, t(9;11) (p23;q24). Therefore, the fetus has inherited a derivative chromosome 11 derived from the maternal translocation, and her karyotype was 46, XX, der(11) t(9;11) (p23;q24) mat.</p><p><b>CONCLUSION</b>SNP-Array combined with high resolution GTG banding has confirmed that the fetus has a derivative chromosome 11 derived from her mother's balanced translocation, resulting in partial 9p trisomy and partial 11q monosomy. This couple therefore have a high recurrence risk. SNP-Array is capable of detecting small chromosomal imbalance in abnormal fetuses and can pinpoint the breakpoints. It therefore has the advantage for the detection of unbalanced translocation which is difficult to detect with GTG banding, which is important for assessment the recurrence risk for cryptic balanced translocation carriers.</p>

Cytogenetic and molecular study of a patient with severe oligozoospermia and asthenozoospermia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore genetic etiologies of a patient with severe oligozoospermia and asthenozoospermia.</p><p><b>METHODS</b>G-banded karyotyping and fluorescence in situ hybridization (FISH) were used to characterize the origin and structure of the abnormal chromosome discovered in this patient. Multiplex polymerase chain reaction (PCR) was used to detect microdeletion of azoospermia factor (AZF).</p><p><b>RESULTS</b>G-banding revealed a karyotype of 45,X,der(15) (?::p11.2→ qter)dn for the patient. Dual-color FISH confirmed that SRY gene was present in a segment attached to the short arm of chromosome 15. Sex chromosome mosaicism and numerical abnormality therefore were both present. Dual-color FISH revealed karyotype of nuc ish(DXZ1× 1, SRY× 1)[390/400]/(DXZ1× 2, SRY× 1) [10/400]. Four-color FISH showed that the abnormal chromosome 15 has derived from a pseudodicentric (Y;15) translocation, and that the breakpoint on Y chromosome was located at Yq12. G-banding and FISH results confirmed that the karyotype was 45,X,der(15)(?::p11.2→ qter)dn.ish psu dic(15;Y)(p11.2;q12)(D15Z1+ , SNRPN+ , PML+ ; SRY+ , DYZ3+ , DYZ1+ ). Microdeletion of AZFc combined with sY254 deletion was detected by multiplex PCR.</p><p><b>CONCLUSION</b>Cytogenetic and molecular genetic analysis of the patient has indicated meiotic disturbances with spermatogenetic arrest resulting from a pseudodicentric chromosome derived from Y;15 translocation and spermatogenesis dysfunction resulting from partial deletion of AZFc region.</p>

Cytogenetic and molecular genetic study of fetal supernumerary marker chromosomes and derivative chromosomes / 中华围产医学杂志

Objective To investigate the prenatal diagnosis and phenotypic assessment strategies for fetal supernumerary marker chromosomes and derivative chromosomes. Methods Five cases of fetal supernumerary marker chromosomes and one case of fetal derivative chromosomes were diagnosed in the First Affiliated Hospital of Sun Yat-Sen University from March 12, 2010 to November 9, 2012 by conventional chromosome banding, fluorescence in situ hybridization (FISH) and spectral karyotyping (SKY). These cases were retrospectively reviewed. Combined with the results of ultrasonography, abnormal phenotypes and pregnancy outcomes were evaluated in these cases. Results All of the five supernumerary marker chromosomes were de novo, in which two were mosaic and the remaining three cases were non-mosaic. Of these five cases, two were type 47, XX+mar and ultrasound indicated abnormal phenotypes. FISH and SKY confirmed that they were derived from chromosome 4 and 22, respectively. The other three cases were marker chromosome with Turner syndrome karyotype (abnormal phenotypes were not found by ultrasound), in which two cases were derived from chromosome Y (by FISH) and one case was identified as ring chromosome X (by FISH and SKY). One de novo derivative chromosome was verified as a product of reciprocal translocation between chromosome 2 and 6 (by FISH and SKY). Induced abortion was performed in all cases between 25 and 32 gestational weeks. Conclusions By combining conventional chromosome banding, FISH and SKY, the origin and content of supernumerary marker chromosomes and derivative chromosomes can be identified. On this basis, clinical phenotype evaluation and genetic counseling may be offered with the ultrasonographic result.

Investigation of ultrasound markers in screening fetal trisomy 21 / 中华妇产科杂志

Objective To investigate the clinical value of ultrasound markers in screening fetal trisomy 21.Methods From Jan.2001 to Dec.2011,a retrospective study about sonographic information of 138 fetuses diagnosed as trisomy 21 was taken in the First Affiliated Hospital of Sun Yat-sen University.All fetuses were divided into 3 groups:isolated ultrasound markers,non-isolated ultrasound markers,and isolated structural malformations or other abnormalities.The relationship between trisomy 21 and ultrasound markers as well as structural anomalies or other abnormalities was analyzed.Results Sonographic anomalies were detected in 132 fetuses(95.7％,132/138),including ultrasound markers and structural malformations or other abnormalities.One hundred and twenty cases(87.0％,120/138)had ultrasound markers,38(31.7％,38/120)had one marker and 82(68.3％,82/120)had more than one marker (P ＜ 0.01).Fifty-one fetuses(37.0％,51/138)had isolated ultrasound markers and non-isolated markers were found in 69 fetuses(50.0％,69/138).Only 12 fetuses(8.7％,12/138)had isolated structural malformations or other abnormalities.In 20 fetuses on whom the first-trimester ultrasound screening were performed,all had ultrasound markers,95％(19/20)had thickened nuchal translucency and 55％ (11/20)had nasal bone hypoplasia.The most common ultrasound markers on the second-trimester screening were nasal bone hypoplasia,which accounted for 41.9％(52/124)cases,followed by thickened nuchal fold (25.0％,31/124),short fenurs and humerus(24.2％,30/124),echogenic intracardiac focus(16.1％,20/124),mild ventriculomegaly(15.3％,19/124),hyperechoic bowel(12.9％,16/124),mild renal pyelectasis(12.1％,15/124).Furthermore,thc common structural malformations or other abnormalities were as follows:cardiac defects(33.1％,41/124),digestive system(26.6％,33/124).Condusions Ultrasound markers are valuable for screening fetal trisomy 21.The fetuses of trisomy 21 usually had more than one ultrasound markers or associated with other abnormalities.Combinations of ultrasound markers with the results of serum screening and maternal age are necessary for evaluation.

Invasive prenatal diagnostic procedures in twin gestations / 中华围产医学杂志

Objective To evaluate the effectiveness and safety of invasive procedures of prenatal diagnosis for twin gestations through analysing the results and outcomes of twins.Methods Invasive prenatal diagnostic procedures guided by ultrasound were introduced to 164 twin pregnancies with various indications,including 111 amniocentesis,and 53 cordocentesis.The results of prenatal diagnosis,complications and outcomes of these twins were analyzed with Chi-square test or Fisher's exact test.Results (1) Chromosome was examined in 261 fetuses and 6.13% (16/261)had abnormal karyotypes.(2) Comparing amniocentesis with cordocentesis,the fetal loss rate within two weeks after the procedure were 0.00% (0/191) and 3.85% (3/78),respectively (P=0.024).The total fetal loss rate and preterm delivery rates in amniocentesis and cordocentesis group were 3.87% (6/155) and 5.45% (3/55),51.22% (42/82)and 38.71% (12/31),respectively (P=0.235and 0.618).(3) Selective feticide was performed on 18 cases after prenatal diagnosis.Fifteen cases had survival neonates,two cases suffered from spontaneous abortion,and two cases had preterm labor with neonatal death.Conclusions (1) Invasive prenatal diagnostic procedures are effective and feasible in twins.Amniocentesis is a relative safer and simpler alternative to cordocentesis,which demanding higher skill and carrying higher fetal loss rate.(2) Mid-trimester selective feticide after prenatal diagnosis appears safety.Before the procedure,the chorionicity and fetal condition should be considered,in order to choose suitable feticide procedures.

Clinical features of abnormal chromosome karyotypes in twin pregnancies complicated with structural abnormalities / 中华妇产科杂志

ObjectiveTo investigate the clinical features of the abnormal chromosome karyotypes in twin pregnancies complicated with fetal malformations. Methods Totally 181 twin pregnancies (362 fetuses) in which one or two fetuses had abnormalities diagnosed by ultrasound were referred to the First Affiliated Hospital of Sun Yat-Sen University from January, 2000 to September, 2010. They were divided into different groups according to ( 1 ) maternal age: the cases with maternal age ≥35 were divided into advanced pregnancy group ( 105 fetuses) , and those with maternal age ＜35 were divided into young pregnancy group (203 fetuses) ; ( 2 ) conceived method : those conceived by assisted reproductive technology were divided into assisted reproductive group (81 fetuses), and the natural conception pregnancies were divided into natural conception group (227 fetuses) ; ( 3 ) chorionicity: the monochorionic twin (MCT) pregnancies were divided into MCT group( 123 fetuses), and the dichorionic twin (DCT) pregnancies were divided into DCT group( 185 fetuses); (4) structural abnormalities: 205 fetuses with structural abnormalities were divided into the abnormal fetal group, and 103 fetuses without structural abnormalities were divided into the normal fetal group. All fetuses were examined by the ultrasound and chromosomes were examined in 308 fetuses. Results( 1 ) The karyotype of fetuses: among 181 twin pregnancies, 23 cases had chromosomal abnormalities in 1 or 2 fetuses ( 12. 7％ ,23/181 ), and chromosomes were exarmined in both fetuses in 20 of 23 cases. Twenty-six of 308 fetuses were found with abnormal chromosomes ( 8.4％, 26/308 ) , and the aneuploid was the most common type of abnormal karyotypes ( 53.8％ , 14/26 ). Twenty-one of 205 fetuses with malformations were found with abnormal karyotypes (10. 2％, 21/205 ). (2) Seven of 123 fetuses in MCT group were with abnormal karyotypes (5.7％, 7/123), and 19 of 185 fetuses in DCT group were with abnormal karyotypes ( 10. 3％, 19/185 ). There was no statistical difference of abnormal chromosome incidence between the two groups. There were 14 fetuses with aneuploid in DCT group ( 7.6％, 14/185 ) ;but there was no fetus with aneuploid in MCT group. There was statistical difference between these two groups. In two cases of DCT group, only one fetus with malformation received chromosome examination because another fetus was dead, and the karyotypes were trisomy 21 and trisomy 18 respectively. Both fetuses of the rest 17 cases received chromosome examination, and the chromosomes of both fetuses in each pregnancy were different. Fifteen of 19 fetuses with abnormal chromosomes in DCT group were complicated with structural abnormalities, and 7 fetuses of 4 twin pregnancies in MCT group were with chromosomal abnormalities. (3) The comparison of the abnormal karyotype incidence between the advanced pregnancy group and young pregnancy group: the abnormal karyotype incidence of the advanced pregnancy group was 7. 6％ (8/105), and that was 8.9％ (18/203) in young pregnancy group. There was no statistical difference between the two groups ( P ＞ 0. 05 ). Six of 105 fetuses in advanced pregnancy group were aneuploids (5. 7％, 6/105), and 8 of 203 fetuses in young pregnancy group were aneuploids (3.9％, 8/203). The aneuploid incidence in advanced pregnancy group was significantly higher than that in young pregnancy group ( P ＜ 0. 05 ). (4) The comparison of the abnormal karyotype incidence between the assisted reproductive group and the natural conception group: 11 of 81 fetuses were with the abnormal karyotypes in assisted reproductive group ( 13. 6％, 11/81 ), and 15 of 227 fetuses were with the abnormal karyotypes in assisted reproductive group (6. 6％, 15/227). There was statistical difference between the two groups ( P ＜0. 05). There were 7 fetuses with the aneuploid in assisted reproductive group ( 8. 6％, 7/81 ) and 7 fetuses with the aneuploid in natural conception group ( 3. 1％, 7/227 ), which showed no statistical difference ( P ＞0. 05 ).(5) The comparison of the abnormal karyotype incidence between the abnormal fetal group and normal fetal group: 21 of 205 fetuses in abnormal fetal group were with abnormal karyotypes (10. 2％, 21/205), and 5 of 103 fetuses in normal fetal group were with abnormal karyotypes ( 4. 9％, 5/103 ) . There was no statistical difference (P ＞ 0. 05 ). 13 fetuses in abnormal fetal group were with the aneuploid (6. 3％, 1 3/205), and only one fetus in normal fetal group was aneuploid (1.0％, 1/103 ). There was statistical difference between the two groups ( P ＜ 0. 05 ). ConclusionsAneuploid is the most common abnormal karyotype in twin pregnancy complicated with fetal abnormalities, especially trisomy 21. Aneuploid mainly occurs in only one fetus of DCT, and chromosomal discordance is usually found in DCT. While in MCT, the twin fetuses with the same abnormal karyotype may have different pbenotypes. The results suggest that it is necessary to analyze both karyotypes of twins even if only one fetus is complicated with structural abnormalities.

Genetic analysis of chorionic villi specimen in spontaneous abortion using various methods / 中华妇产科杂志

Objective To explore the efficacy of multiplex ligation-dependent probe amplification (MLPA)combined with fluorescence in situ hybridization(FISH)and comparative genomie hybridization (CGH)combined with FISH in genetic analysis of chorionic villi specimen(CVS)of spontaneous abortion.Methods CGH+FISH and MLPA+FISH were used for genetic analysis of 29 CVS from spontaneous abortion and 6 normal CVS from selective abortion,in the mean time,those results were compared with conventional eytogenetic karyotyping.Results The report time were 40 hours in MLPA+FISH and 120 houm in CGH+FISH.The mean time of chorionic villi culture was(240±72)hours.The successful rate of specimen analysis were 97%(34/35)in CGH,100%(35/35)in MLPA,100%(35/35)in FISH and 91%(32/35)in conventional cytogenetic karyotyping.Apart from 1 case failed in CGH analysis,the results from MLPA+FISH were almost similar to that from CGH+FISH,however,that 1 specimen failed in CGH were detected successfully by MLPA+FISH.The discrepancy rate were 13%(4/31)in CGH+FISH and 12%(4/32)in MLPA+FISH respectively when compared with conventional cytogenetic analysis.Conclusions MLPA+FISH analysis present shorter detecting time and achieve 100%tale of successful report.This combined method was an important adjuvant approach to conventional cytogenetic karyotyping in CVS from spontaneous abortion.