Prenatal diagnosis of microdeletion 16p13.11 combination with partial monosomy of 2q37.1-qter and partial trisomy of 7p15.3-pter in a fetus with bilateral ventriculomegaly, agenesis of corpus callosum, and polydactyly

ObjectiveTo present a prenatal diagnosis of microdeletion 16p13.11 with partial monosomy of 2q37.1-qter and partial trisomy of 7p15.3-pter in a fetus with bilateral ventriculomegaly, agenesis of corpus callosum, and polydactyly.Case ReportA 41-year-old well-being Taiwanese, nulligravida woman received amniocentesis at a gestational age of 18 weeks for advanced maternal age. The fetus' karyotype showed 46,XY,der(2)t(2;7)(q36.2;p15.1). Both parents also received cytogenetic examinations and the mother's karyotype revealed 46,XX,t(2;7)(2q36.2;p15.1). High-resolution ultrasound showed the fetus had bilateral ventriculomegaly, agenesis of corpus callosum, and polydactyly of the right hand. After the termination of this pregnancy, the whole genome oligonucleotide-base array comparative genomic hybridization (CGH) by using fetal skin cells demonstrated a 8.44-Mb deletion at 2q37.1 (234602276-243041305), a 22.8-Mb duplication (65558-22869338) at 7p15.3, and an additional 1.32-Mb deletion (14968855-16292235) at 16p13.11.ConclusionArray CGH is a useful tool not only to discover the genomic imbalance at the breakpoints as well as to detect unexpectedly complex rearrangements in other chromosomes. Our case also provided evidence that genomic aberration at chromosome 16p13.11 involves in the formation of polydactyly.     

De novo monosomy 9p24.3-pter and trisomy 17q24.3-qter characterised by microarray comparative genomic hybridisation in a fetus with an increased nuchal translucency

OBJECTIVES: Increased nuchal translucency (NT) during the first trimester of pregnancy is a useful marker to detect chromosomal abnormalities. Here, we report a prenatal case with molecular cytogenetic characterisation of an abnormal derivative chromosome 9 identified through NT. METHODS: Amniocentesis was performed because of an increased NT (4.4 mm) and showed an abnormal de novo 46,XX,add(9)(p24.3) karyotype. To characterise the origin of the small additional material on 9p, we performed a microarray comparative genomic hybridisation (microarray CGH) using a genomic DNA array providing an average of 1 Mb resolution. RESULTS: Microarray CGH showed a deletion of distal 9p and a trisomy of distal 17q. These results were confirmed by FISH analyses. Microarray CGH provided accurate information on the breakpoint regions and the size of both distal 9p deletion and distal 17q trisomy. The fetus was therefore a carrier of a de novo derivative chromosome 9 arising from a t(9;17)(p24.3;q24.3) translocation and generating a monosomy 9p24.3-pter and a trisomy 17q24.3-qter. CONCLUSION: This case illustrates that microarray CGH is a rapid, powerful and sensitive technology to identify small de novo unbalanced chromosomal abnormalities and can be applied in prenatal diagnosis.     

Prenatal diagnosis of inherited satellited non-acrocentric chromosomes

We report on the prenatal diagnosis of two sib female fetuses with a satellited short arm of chromosome 4 and a male fetus with a satellited long arm of chromosome X. The first two fetuses had a cryptic balanced translocation (4;15)(p16;p11.1) inherited from a mother carrying a satellited 4p and having an affected child with the Wolf-Hirschhorn syndrome. The third fetus had a satellited Xq, with a deletion of subtelomeric region of Xq. The mother was subsequently found to have the same satellited Xq but without the presence of a reciprocal translocation. She decided to continue the pregnancy. The proband with a satellited Xq manifested developmental delay, mental retardation, hypertelorism, ptosis of one eye, low-set ears, and hearing disturbance at age 6 months. Fluorescence in situ hybridization (FISH) with a specific telomeric or subtelomeric probe, and genetic marker analyses were used to confirm the diagnosis. Pregnant women with satellited non-acrocentric chromosomes are at risk for carrying fetuses with chromosome abnormalities. If the X chromosome is involved, the fetuses can be affected with X-linked recessive disorders including mental retardation. Detailed genetic counselling, cytogenetic studies, FISH and genetic marker analyses are useful in prenatal detection of abnormal chromosome rearrangements.     

Prenatal findings and delineation of de novo concurrent partial trisomy 7q(7q31.2 → qter) and partial monosomy 6q(6q26 → qter) by high-resolution array CGH

Objective.?We investigated the application of microarray-based comparative genomic hybridization (array CGH) on a fetus showing hemivertebrae and intra-abdominal mass at 15 weeks.

Methods. Conventional karyotyping and high-resolution array CGH techniques using 244K CGH microarray were performed to investigate the possibility of genomic imbalance on the opted chorionic villus sample.

Results.?G-banded fetal chromosome analysis showed 46,XY,der(6)t(6;7)(q26;q31.2)pat. Whole genome scan by array CGH fine mapped the origin of the aberrant chromosomes to be a partial single copy gain of 42.5 Mb from chromosome region 7:116266547 → qter and concurrent partial single copy loss of 8.1 Mb from chromosome region 6:162756975 → qter. Pathological examination of the abortus showed gastrointestinal malformations, hemivertebrae with scoliosis, clinodactyly and club feet.

Conclusions.?Prenatal and perinatal findings of concurrent trisomy 7q and monosomy 6q were unique. This study demonstrated array CGH can interrogate the entire genome at a resolution and rapidity unattainable by conventional cytogenetic techniques and may have wide application in prenatal diagnosis.     

Submicroscopic chromosomal abnormalities in fetuses with increased nuchal translucency and normal karyotype

Objective: To investigate the submicroscopic chromosomal abnormalities in fetuses with increased nuchal translucency (NT) and normal karyotype.

Methods: Total of 296 fetuses with increased NT (≥3.0?mm) were tested by conventional karyotyping. When cytogenetic analysis showed normal chromosome, the pregnancies were then consulted for array-comparative genomic hybridization (CGH) analysis and received subsequent morphology scan between 20 and 24 weeks gestation. Submicroscopic chromosomal abnormalities were assessed and compared between the fetuses with and without structural defects.

Results: Chromosomal abnormality was identified in 19.9% (59/296) fetuses. Two hundred and twenty samples were tested by array CGH. Submicroscopic chromosomal abnormalities were detected in 9.1% (20/220) fetuses. For the fetuses with abnormal morphology scan, the detection rate of submicroscopic chromosomal abnormalities was higher than those with normal morphology scan (26.9% versus 6.7%, p?Conclusions: Submicroscopic chromosomal abnormalities should be accessed when the fetus was found to be with increased NT and normal karyotype, especially when the structural defects were found at second or third trimester.     

Larsen-like phenotype associated with partial trisomy 3p and monosomy 5p

BACKGROUND: We report on a fetus with radiographic features of Larsen Syndrome (LS) and unbalanced 3;5 translocation. Recently LS was shown to be caused by mutations in FLNB gene which maps on 3p14.3. METHODS: Comparative genomic hybridization (CGH) was performed to search for genomic imbalances. Fluorescence in situ analysis (FISH) was done with BAC clone RP11-754F19 probe from the FLNB gene region (3p14.3). RESULTS: CGH showed a large loss of the chromosome 5 short arm and a gain of half of the short arm of chromosome 3 resulting from a derivative chromosome 5. FISH analysis with FLNB probe demonstrated that it was not triplicated. Thus, we excluded the role of a gene dosage effect of FLNB in abnormal craniofacial development in this fetus. CONCLUSIONS: To our knowledge, this is the first report of Larsen-like phenotype associated with unbalanced translocation resulting in partial trisomy 3p and monosomy 5p.     

Inv dup del(10p): Prenatal diagnosis and molecular cytogenetic characterization

ObjectiveWe present molecular cytogenetic characterization of prenatally detected inverted duplication and deletion of 10p [inv dup del(10p)].Case reportA 39-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a derivative chromosome 10 with additional material at the end of the short arm of one chromosome 10. Simultaneous array comparative genomic hybridization (aCGH) analysis revealed the result of arr 10p15.3 (136,361–451,013) × 1, 10p15.3p12.1 (536,704–25,396,900) × 3 [GRCh37 (hg19)] with a 0.31-Mb deletion of 10p15.3 encompassing ZMYND11 and DIP2C, and a 24.86-Mb duplication of 10p15.3p12.1. The pregnancy was subsequently terminated, and a female fetus was delivered with facial dysmorphism. Postnatal aCGH analysis showed that the umbilical cord had the same result as that of amniotic fluid, whereas the placenta had only the deletion of 10p15.3. Fluorescence in situ hybridization (FISH) analysis of the cord blood confirmed inverted duplication and deletion of 10p. The cord blood had a karyotype of 46,XX,der(10) del(10) (p15.3)dup(10) (p15.3p12.1)dn. Polymorphic DNA marker analysis confirmed a maternal origin of the chromosome 10 aberration.ConclusionPrenatal diagnosis of inv dup del(10p) with haploinsufficiency of ZMYND11 should include a genetic counseling of mental retardation and chromosome 10p15.3 microdeletion syndrome. aCGH, FISH and polymorphic DNA marker analysis are useful for perinatal investigation of inv dup del(10p).     

Prenatal diagnosis and molecular cytogenetic analysis of partial monosomy 10q (10q25.3-->qter) and partial trisomy 18q (18q23-->qter) in a fetus associated with cystic hygroma and ambiguous genitalia

OBJECTIVES: To present the prenatal diagnosis and molecular cytogenetic analysis of a fetus with nuchal cystic hygroma and ambiguous genitalia. CASE AND METHODS: Amniocentesis was performed at 16 weeks' gestation because of the abnormal fetal sonographic finding of a large septated nuchal cystic hygroma. Genetic amniocentesis revealed a terminal deletion in the long arm of chromosome 10. The paternal karyotype was subsequently found to be 46,XY,t(10;18)(q25.3;q23). The maternal karyotype was normal. The pregnancy was terminated. A hydropic fetus was delivered with a septated nuchal cystic hygroma and ambiguous genitalia. Fluorescence in situ hybridization (FISH), microarray-based comparative genomic hybridization (CGH), and polymorphic DNA markers were used to investigate the involved chromosomal segments. RESULTS: FISH study showed absence of the 10q telomeric probe and presence of the 18q telomeric probe in the derivative chromosome 10. Microarray-based CGH analysis showed loss of distal 10q and gain of distal 18q. Polymorphic DNA marker analysis determined the breakpoints. The fetal karyotype was 46,XY,der(10)t(10;18)(q25.3;q23)pat. The chromosome aberration resulted in partial monosomy 10q (10q25.3-->qter) and partial trisomy 18q (18q23-->qter). CONCLUSIONS: The present case provides evidence that partial monosomy 10q (10q25.3-->qter) with partial trisomy 18q (18q23-->qter) can be a genetic cause of fetal cystic hygroma and ambiguous genitalia. Cytogenetic analysis for prenatally detected structural abnormalities may detect unexpected inherited chromosome aberrations.     

Partial monosomy 13q (13q21.32--->qter) and partial trisomy 8p (8p1--->pter) presenting with anencephaly and increased nuchal translucency: array comparative genomic hybridization characterization

ObjectiveTo present array comparative genomic hybridization (aCGH) characterization of partial monosomy 13q (13q21.32→qter) and partial trisomy 8p (8p12→pter) presenting with anencephaly and increased nuchal translucency (NT).Case ReportA 34-year-old primigravid woman was referred to the hospital at 12 weeks of gestation for termination of the pregnancy because of major structural abnormalities of the fetus. Prenatal ultrasound revealed a malformed fetus with anencephaly and an increased NT thickness of 5 mm at 12 weeks of gestation. Cytogenetic analysis of the fetus revealed a derivative chromosome 13. The mother was subsequently found to carry a balanced reciprocal translocation between 8p12 and 13q21. Bacterial artificial chromosome-based aCGH using fetal DNA demonstrated partial trisomy 8p and partial monosomy 13q [arr cgh 8p23.3p12 (RP11-1150M5→RP11-1145H12)×3, 13q21.32q34 (RP11-326B4→RP11-450H16)×1]. Oligonucleotide-based aCGH showed a 36.7-Mb duplication of distal 8p and a 48.4-Mb deletion of distal 13q. The fetal karyotype was 46,XY,der(13) t(8;13)(p12;q21.32)mat. The maternal karyotype was 46,XX,t(8;13)(p12;q21.32).ConclusionThe 13q deletion syndrome can be associated with neural tube defects and increased NT in the first trimester. Prenatal sonographic detection of neural tube defects should alert chromosomal abnormalities and prompt cytogenetic investigation, which may lead to the identification of an unexpected parental translocation involving chromosomal segments associated with neural tube development.     

Prenatal diagnosis of a de novo complex chromosomal rearrangement involving four chromosomes

A complex chromosome rearrangement, apparently a balanced translocation involving chromosomes 4, 6, 15 and 16, was found in cultured cells of amniotic fluid from a 32-year-old primigravida who requested amniocentesis for prenatal diagnosis because of a family history of mental retardation. Chromosome analysis of peripheral blood from both parents were normal. The couple was counselled for the prenatal diagnosis of this de novo complex translocation and, subsequently, elected to terminate the pregnancy. Post-mortem examination revealed a 23-week fetus with intrauterine growth retardation. The identical chromosome rearrangement was subsequently confirmed in cultured fibroblasts from skin and cord obtained from the abortus. To our knowledge, this is the first report where routine prenatal diagnosis revealed a fetus with a balanced complex chromosomal rearrangement involving four chromosomes of de novo origin.     

Microphthalmia with linear skin defects (MLS) syndrome evaluated by prenatal karyotyping, FISH and array comparative genomic hybridization

OBJECTIVE: To explore the utility of comparative genomic hybridization to BAC arrays (array CGH) for prenatal diagnosis of microphthalmia and linear skin defects syndrome. METHODS: We used karyotype analysis, FISH and array CGH to investigate an X;Y translocation. Replication studies were done on cultured amniocytes and lymphoblasts. RESULTS: We describe a severe case of MLS syndrome that presented prenatally with multiple anomalies including cystic hygroma, microphthalmia, intrauterine growth restriction and a complex congenital heart defect. Cytogenetic analysis of amniocytes revealed an unbalanced de novo translocation between chromosomes X and Y [karyotype 46,X,der(X)t(X;Y)(p22.3;q11.2).ish der(X)(DXZ1+,DMD+,KAL-,STS-,SRY-),22q11.2 (Tuple1 x 2)]. MLS diagnosis was made at birth and the prenatal karyotype was confirmed. Replication studies showed the derivative X chromosome was the inactive X. Array CGH confirmed the X and Y imbalances seen in the karyotype and also showed twelve BACs in the MLS region were deleted as a result of the translocation. FISH with BAC clones verified the array findings and placed the X breakpoint in Xp22.2, resulting in the amended karyotype, 46,X,der(X)t(X;Y)(p22.2;q11.2).ish der(X)(DXZ1+,DMD+,KAL-,STS-,SRY-),22q11.2(Tuple1 x 2) arr cgh Xp22.33p22.2(LLNOYCO3M15D10 -->GS1-590J6)x 1,Yq11.222q23(RP11-20H21-->RP11-79J10)x 1. CONCLUSION: The sensitivity of array CGH was valuable in detecting monosomy of the MLS critical region. Array CGH should be considered for the prenatal diagnosis of this syndrome.     

Prenatal diagnosis of autosomal dominant polycystic kidney disease using flanking DNA markers and the polymerase chain reaction.

A prenatal diagnosis was carried out on a 9-week-old fetus at risk for autosomal dominant polycystic kidney disease (ADPKD). Ten members of the family were previously typed using five DNA markers linked to the PKD1 locus on chromosome 16, and one marker linked to the putative PKD2 locus on chromosome 2. The polymerase chain reaction (PCR) was used to amplify the D16S125 locus. Pairwise and multipoint lod scores indicated that the family was most likely segregating a PKD1 mutation. The fetus inherited the disease haplotype from the affected parent. Diagnostic accuracy was greater than 99 per cent, taking into account the possibility of genetic heterogeneity.     

Cytogenetical diagnosis in paraffin-embedded fetoplacental tissue using comparative genomic hybridization

Comparative genomic hybridization (CGH) is a FISH-related technique used to assess global chromosomal aberrations in a variety of human tumours. Recently CGH has been applied to cytogenetic analysis of fresh frozen fetoplacental tissues. Here we report the application of CGH to paraffin-embedded placental samples. Ten samples from paraffin-embedded blocks of 6 control placentas and fetoplacental tissue from 10 aneuploidies, and 2 unbalanced aberrations were evaluated. Balanced karyotype profiles were obtained from samples of healthy placentas and all samples from the same placenta appeared to have similar confidence intervals. CGH analysis of four cases of trisomy 21, three cases of trisomy 18, one case of trisomy 13, one case of trisomy 15 and one case of trisomy 7 all showed overrepresentation of the respective trisomic chromosome. The CGH profile was also in accordance with the karyotyping of a case with isochromosome 21. The CGH profile of a case with der (2)t(2;6)(q37.3;q22.2) revealed partial trisomy for chromosome 6 between q21 and q27. CGH may be a useful adjunct in prenatal genetic diagnosis when retrospective diagnosis is needed from archival samples.     

Characterization of a balanced complex chromosomal rearrangement carrier ascertained through a fetus with dup15q26.3 and del5p15.33: case report

Abstract

Complex chromosomal rearrangements (CCRs) are structural aberrations involving more than two chromosomes which rarely appear in individuals with normal phenotypes. These individuals report fertility problems, recurrent miscarriages, or congenital anomalies in newborn offspring as a consequence of either meiotic failure or imbalanced chromosome segregation. A CCR involving chromosomes 5, 15, and 18 was discovered in a phenotypically normal man through a fetus with congenital malformations and partial trisomy of chromosome 15 and monosomy of chromosome 5. Ultrasound examination at 20 weeks of gestation showed severe oligoamnios and hydrothorax. Prenatal cytogenetic analysis and array comparative genomic hybridization (array-CGH) revealed a female fetus with dup15q26.3 and del5p15.33. We diagnosed the CCR using three-color fluorescence in situ hybridization (three-color FISH), and a balanced CCR using array-CGH and FISH was diagnosed in the paternal karyotype. The father is a carrier of a balanced translocation 46,XY,t(5;15;18)(p15.31;q26.3;p11.2). Due to the complexity of these rearrangements the diagnosis is difficult and the reproductive outcome uncertain. Reporting such rare cases is important to enable such information to be used for genetic counseling in similar situations and help estimate the risk of miscarriage or of newborns with congenital abnormalities.     

Del(18p) syndrome with increased nuchal translucency in prenatal diagnosis

We report a de novo translocation between chromosome 15 and 18 resulting in monosomy 18p in prenatal diagnosis. The patient was referred for amniocentesis due to increased nuchal translucency (INT) (5 mm) at 13.6 weeks of gestation. Karyotype of the fetus revealed 45,XX,der(15;18)(q10;q10) in all metaphases. The targeted fetal ultrasound at 20 weeks of gestation did not show any special physical abnormalities other than 6.4 mm of nuchal fold thickness. Molecular cytogenetic findings using CGH and FISH confirmed the del(18p) with dicentromeres from both chromosome 15 and 18. The present study shows that the INT at first trimester was the only prenatal finding for the fetus with del(18p) syndrome and that molecular cytogenetic methods are useful for detecting chromosomal aberrations precisely.     

Pure partial monosomy 3p (3p25.3 → pter): Prenatal diagnosis and array comparative genomic hybridization characterization

ObjectiveThe purpose of this case report is to present prenatal diagnosis and molecular cytogenetic characterization of pure partial monosomy 3p (3p25.3 → pter) by array comparative genomic hybridization (aCGH) and quantitative fluorescent polymerase chain reaction (QF-PCR) on uncultured amniocytes.Case ReportA 35-year-old, gravida 2, para 0, woman underwent amniocentesis at 19 weeks of gestation because of advanced maternal age. Her husband was 37 years of age. She had experienced one intrauterine fetal death. Amniocentesis during this pregnancy revealed a distal deletion of chromosome 3p. The parental karyotypes were normal. Prenatal ultrasonography findings were unremarkable. At 22 weeks of gestation, she underwent repeated amniocentesis, and aCGH investigation using CytoChip Oligo Array on uncultured amniocytes revealed a 9.29-Mb deletion of 3p26.3p25.3 [arr 3p26.3p25.3 (64,096–9,357,258 bp) ×1] encompassing the genes of CHL1, CNTN4, CRBN, LRRN1, ITPR1, and SRGAP3, but not involving the markers D3S1263 and D3S3594. Polymorphic DNA marker analysis on uncultured amniocytes showed a paternal origin of the deletion. Cytogenetic analysis of cultured amniocytes revealed a karyotype of 46,XX,del(3)(p25.3). At 24 weeks of gestation, prenatal ultrasonography findings of the brain, heart, and other internal organs were unremarkable. The pregnancy was subsequently terminated, and an 886-g female fetus was delivered with brachycephaly, hypertelorism, a short and thick nose, micrognathia and low-set ears.ConclusionIn this case, aCGH has characterized a 3p deleted region with haploinsufficiency of the neurodevelopmental genes associated with cognitive deficit and mental retardation but without involvement of the congenital heart disease susceptibility locus, and QF-PCR has determined a paternal origin of the deletion. aCGH and QF-PCR help to delineate the genomic imbalance in prenatally detected de novo chromosome aberration, and the information acquired is useful for genetic counseling.     

Detecting sex chromosome anomalies and common triploidies in products of conception by array-based comparative genomic hybridization

OBJECTIVES: In recent years, array-based comparative genomic hybridization (array CGH) has moved to the forefront of molecular cytogenetics with its ability to rapidly characterize chromosome abnormalities at resolutions much higher than routine chromosome banding. However, array CGH, like all CGH procedures, has heretofore been deemed unable to detect ploidy, a major cause of fetal demise and spontaneous miscarriage. METHOD: We recently developed a CGH microarray that is designed for detecting aneuploidy and unbalanced chromosome rearrangements. Here, we introduce the use of a Klinefelter male cell line (47,XXY) as a control for array CGH analyses on products of conception (POCs). RESULTS: This approach facilitates the detection of common trisomies and monosomies of the sex chromosomes by reducing the analysis to the identification of single copy gains or losses. Furthermore, in a blinded study, careful interpretation of the microarray results with particular attention to the sex chromosome ratios between the patient sample and the control allowed for the detection of some common triploidies. CONCLUSION: These results suggest that using a chromosomally abnormal cell line in array CGH analysis can be applied to other CGH platforms and that array CGH, when properly performed and analyzed, is a powerful tool that can detect most chromosomal abnormalities observed in a clinical setting including some polyploidies.     

Prenatally diagnosed de novo segmental amplification or deletion by microarray-based comparative genomic hybridization: A retrospective study

ObjectivePrenatal diagnosis of de novo segmental amplification or deletion by microarray-based comparative genomic hybridization (array CGH) is uncommon. The study aimed to know about the incidence, abnormal ultrasound findings, and pregnancy outcomes of prenatally diagnosed de novo segmental amplification or deletion by array CGH.Materials and methodsBetween January 2014 and December 2017, we analyzed pregnant women who received prenatal array CGH (SurePrint G3 Human CGH Microarray Kit, 8 × 60K) at Chang Gung Memorial Hospital, Taiwan. Clinical data on maternal age, reason for fetal karyotyping, sonographic findings, gestational age at delivery, newborn birth weight, and associated anomalies, if any, were obtained by chart review.ResultsA total of 836 specimens (814 amniotic fluid samples, 4 cord blood samples, 18 chorionic villi samples) were analyzed by array CGH during the study period. Of the 56 cases with abnormal array CGH results, 40 had segmental amplification or deletion, 12 had trisomy, three had monosomy, and one had sex chromosome aneuploidy. Of these 40 cases with segmental amplification or deletion, 30 were inherited and 10 were de novo occurrences. The incidence of de novo segmental amplification or deletion was 1.2% (10/836). Abnormal prenatal ultrasound findings occurred in 40% (4/10) of de novo segmental amplification or deletion cases. Among these 10 pregnancies, nine were voluntarily terminated between 22 and 26 weeks of gestation and one was delivered at term.ConclusionsPrenatal diagnosis of de novo segmental amplification or deletion by array CGH raises important genetic counseling issues. In our series, the incidence of de novo segmental amplification or deletion in prenatal samples was 1.2%. Abnormal prenatal sonographic findings occurred in 40% of these de novo segmental amplification or deletion cases. Of these de novo segmental amplification or deletion pregnancies, 90% were voluntarily terminated.     

先天性疾病研究及产前诊断中Array CGH的应用

染色体微缺失、重复、扩增和非整倍体等基因组DNA失衡是导致胎儿发育迟缓、畸形、死胎、流产和其他先天性疾病的内在原因。微阵列-比较基因组杂交技术（Array CGH）利用基因芯片取代了传统比较基因组杂交技术的正常中期染色体作为杂交靶标,与分别采用不同荧光标记的待测DNA和参照DNA杂交,通过比较两种荧光强度的比率,检测出染色体基因拷贝数变化。Array CGH已成为一个重要的细胞遗传学研究工具,用于产前诊断和先天性疾病诊断染色体亚显微结构异常。