Identification Of Chromosomal Abnormalities Research Articles

Identification of chromosomal abnormalities in miscarriages by CNV-Seq

ObjectiveThe primary object of this study is to analyze chromosomal abnormalities in miscarriages detected by copy number variants sequencing (CNV-Seq), establish potential pathways or genes related to miscarriages, and provide guidance for birth health in the following pregnancies.MethodsThis study enrolled 580 miscarriage cases with paired clinical information and chromosomal detection results analyzed by CNV-Seq. Further bioinformatic analyses were performed on validated pathogenic CNVs (pCNVs).ResultsOf 580 miscarriage cases, three were excluded as maternal cell contamination, 357 cases showed abnormal chromosomal results, and the remaining 220 were normal, with a positive detection rate of 61.87% (357/577). In the 357 miscarriage cases, 470 variants were discovered, of which 65.32% (307/470) were pathogenic. Among all variants detected, 251 were numerical chromosomal abnormalities, and 219 were structural abnormalities. With advanced maternal age, the proportion of numerical abnormalities increased, but the proportion of structural abnormalities decreased. Kyoto Encyclopedia of Genes and Genomes pathway and gene ontology analysis revealed that eleven pathways and 636 biological processes were enriched in pCNVs region genes. Protein–protein interaction analysis of 226 dosage-sensitive genes showed that TP53, CTNNB1, UBE3A, EP300, SOX2, ATM, and MECP2 might be significant in the development of miscarriages.ConclusionOur study provides evidence that chromosomal abnormalities contribute to miscarriages, and emphasizes the significance of microdeletions or duplications in causing miscarriages apart from numerical abnormalities. Essential genes found in pCNVs regions may account for miscarriages which need further validation.

Role of Conventional Cytogenetics and FISH in the Laboratory Work Up of Plasma Cell Dyscrasias

AbstractPlasma cell dyscrasias are a heterogeneous group of neoplasms characterized by abnormal proliferation of plasma cells with or without over production of monoclonal immunoglobulins. Chromosomal abnormalities are acquired either early in the course of the disease or during disease progression. Plasma cell dyscrasias are categorized into multiple cytogenetic subtypes that form an integral component of risk-stratified treatment protocols. The primary genetic events are IgH gene translocations and non-random gains of chromosomes 3/5/7/9/11/15/19 and or 21. The secondary genetic events consist of chromosome 1 abnormalities (1p deletion and 1q gain or amplification), deletion 17p/TP53, deletion 13q, and MYC gene rearrangements. Plasma cells being at the end of differentiation spectrum of B cells, have low proliferative potential precluding the use of karyotyping in identification of chromosomal abnormalities. Analysis of enriched plasma cells using interphase fluorescent in situ hybridization (FISH) is the technique of choice for identifying these abnormalities. It is essential to enrich plasma cells before the FISH analysis, and numerous plasma cell enrichment techniques have been described. In the paper, we review the cytogenetic approach to identify clinically significant genetic aberrations including the effective use of FISH panels and plasma cell enrichment techniques.

Identification of a Novel Unbalanced t(4;8) (q12;q24) in Paediatric Acute Myeloid Leukemia M2 with AML-ETO Negative Patient by Fluorescence in Situ Hybridization Technique

Identification of chromosomal abnormalities in patients with Acute Myeloid Leukemia (AML) has contributed substantially to our current understanding of the molecular pathogenesis underlying leukemogenesis, and risk-stratification. Based on molecular abnormalities both influences treatment strategies and aids in determining prognosis. While over 300 established mutations have been documented in AML, the enhanced availability of genetic analysis and the increase in awareness of uncommon chromosomal translocations have made it possible for rare, apparently unique translocations to become recognized and to ultimately gain prognostic significance. Hence, we present a case of AML with a novel, t(4;8) involving breakpoints previously undescribed. Although the patient required second induction, first remission was ultimately achieved. While the prognostic significance of this translocation is not fully elucidated, it is our hope that documentation of this patient’s presentation will help to characterize the significance of a yet undefined cytogenetic abnormality in AML.

Non-hodgkin Lymphoma of Lymphoid Tissue Associated with Extranodal Mucosa of the Cecum and Acute Appendicitis. Report of a Case

Objective: Presentation of an acute appendicitis and non-Hodgkin lymphoma of lymphoid tissue associated with extranodal mucosa from the cecum clinical case. Introduction: The cecal appendix can be affected by Non-Hodgkin Lymphomas (NHL) by extension of the neoplasm; however primary appendicular lymphoproliferative processes are uncommon. The NHL of Mucosal-Associated Lymphoid Tissue (MALT) is exceptional. To establish the diagnosis of MALT, a morphological, molecular and immunohistochemical diagnosis is required, including molecular techniques that reflect B cell clones, PCR analysis or the identification of chromosomal abnormalities. Methods: 40 year old male, with 15 days of evolution of abdominal pain located in Right Lower Quadrant (RLQ) and associated symptoms like decreased appetite, nausea, and adynamia, who was firstly diagnosticated as an urinary tract infection treated as outpatient; upon his readmission, he was performed CT scan evidencing mesenteric panniculitis and thickening of the appendicular wall; he was surgically intervened finding edematous and congestive vermiform appendix with lower third perforation, and indurated cecum with 2 cm perforation from the appendicular base, performing right hemicolectomy with ileo-transverse mechanical anastomosis; he was discharged home 7 days after the postoperative period; the histopathological study and immunohistochemistry panel was compatible with MALT-type lymphoma, with lesion-free edges. Extension CT scans with no evidence of distant disease. He was sent to oncology for follow-up. Conclusion: It is important to get an established diagnosis in this rare pathology with molecular techniques and not only with histopathological cuts, since 30% of patients relapse.

Identification of Chromosomal Abnormalities in Early Pregnancy Loss Using a High-Throughput Ligation-Dependent Probe Amplification–Based Assay

Embryonic chromosomal abnormalities are the major cause of miscarriage. An accurate, rapid, and cheap method of chromosome analysis in miscarriage is warranted in clinical practice. Thus, a high-throughput ligation-dependent probe amplification (HLPA)-based method of detecting aneuploidies and copy number variations in miscarriage was developed. A total of 1060 cases of miscarriage were assessed. Each specimen was subjected to quantitative fluorescence (QF)-PCR/HLPA and chromosomal microarray analysis (CMA) in parallel. All 1060 samples were successfully analyzed using both methods; of these samples, 1.7% (18/1060) were identified as having significant maternal cell contamination. Among the remaining 1042 cases without significant maternal cell contamination, QF-PCR/HLPA reached a diagnostic yield of 59.6% (621/1042), which is comparable to the yield of 60.3% (628/1042) with CMA. Compared with CMA results, the sensitivity and specificity of QF-PCR/HLPA in the identification of total pathogenic chromosomal abnormalities were 98.9% and 100%, respectively. Furthermore, the overall prevalence of chromosomal abnormalities in cases of spontaneous abortion was not significantly different from that in cases of recurrent miscarriage (61.3% versus 58.5%). In summary, QF-PCR/HLPA rapidly and accurately identified chromosomal abnormalities at a comparable performance and lower cost as compared with CMA. Combining simplicity and accuracy with cost-effectiveness, QF-PCR/HLPA may serve as apromising approach to routine genetic testing in miscarriage in clinical practice.

Breeding and Economic Aspects of Cytogenetic Screening Studies of Pigs Qualified for Reproduction.

Simple SummaryThe cytogenetic screening of pigs, carried out using continually refined cytomolecular techniques, enables a precise diagnosis of chromosomal abnormalities that cause developmental anomalies and considerably reduce the fertility (by several dozen to 100%) and performance parameters of breeding herds, resulting in substantial financial losses. Due to the potential spontaneous occurrence of chromosomal aberrations and the rapid spread of these genetic defects in the population, especially under artificial insemination conditions, it is necessary to perform cytogenetic monitoring of animals qualified for reproduction, which is an important criterion when formulating specific selection guidelines.Cytogenetic monitoring allows the identification and early removal of pigs affected by inherited karyotype defects from breeding herds. These abnormalities cause developmental anomalies, considerably reducing the fertility (by several dozen to 100%) and performance parameters of breeding herds, resulting in substantial financial losses. This mainly concerns reciprocal translocations, typical of pigs, which are highly prevalent (about 0.46%), generally occur de novo, and normally result in low breeding soundness of the carriers. Due to the potential spontaneous occurrence of chromosomal aberrations and the rapid spread of these genetic defects in the population, especially under artificial insemination conditions, it is necessary to perform routine karyotype screening of animals qualified for reproduction. The cytogenetic screening program for young boars, carried out using continually refined diagnostic techniques, permits a precise and reliable karyotype assessment, identification of chromosomal abnormalities, and formulation of specific selection guidelines.

Алгоритм интерпретации клинической значимости хромосомных микродупликаций при недифференцированных формах интеллектуальных расстройств

Идентификация хромосомных аномалий на субмикроскопическом уровне и установление их роли в этиологии интеллектуальных расстройств являются важной научной и практической задачей. Оценка патогенного значения менее изученного типа вариаций копийности ДНК - хромосомных микродупликаций представляет актуальный предмет для обсуждения. В исследовании предложен алгоритм интерпретации клинической значимости частичных трисомий, который является неотъемлемой составляющей в диагностике и профилактике хромосомных болезней. The identification of chromosomal abnormalities at the submicroscopic level and the establishment of their role in the etiology of intellectual disorders are an important scientific and practical task. Evaluation of the pathogenic value of the less studied type of copy number variation - chromosomal microduplication - is an actual issue. The study proposed an algorithm for interpreting the clinical significance of partial trisomies, which is an integral component in the diagnosis and prevention of chromosomal diseases.

Identification of chromosomal abnormalities and genomic features in near-triploidy/tetraploidy-acute leukemia by fluorescence in situ hybridization.

BackgroundNear-triploidy/tetraploidy is rarely found in acute leukemia. Only limited data are available to characterize this condition, and it remains largely unknown.Patients and methodsIn our study, we performed karyotype analysis on 1,031 patients diagnosed with acute leukemia from 2006 to 2018. A total of 10 patients of near-triploidy/tetraploidy karyotype were enrolled. Two cases of near-triploidy (66–79 chromosomes) and eight cases of near-tetraploidy (84–100 chromosomes) were identified. Bone marrow samples of these 10 patients were analyzed by fluorescence in situ hybridization with 19 commercially available probes that detected a small portion of gene alterations and large regions of chromosome amplifications.ResultsOf the six patients with acute myelocytic leukemia, we detected three cases of double t(8;21)(q22;q22) that have not been previously reported, and one of them demonstrated ins(21;8) (q22;q24q22). We also describe a novel pediatric case carrying double t(15;17)(q22;q21) and receiving targeted treatment with all-trans retinoic acid therapy. To date, this case has responded well to the regimen and has shown continuous complete remission. All patients received chemotherapy. One of them received allogeneic hematopoietic stem cell transplant (HSCT) and survived for 22 months. Eight of the 10 patients died, and the median overall survival was 11 months.ConclusionUsing fluorescence in situ hybridization, we identified the distinct complex karyotype of near-triploidy/tetraploidy and provided further prognostic information. Tetraploidy acute promyelocytic leukemia had favorable prognosis; thus, HSCT was not necessary. The case of insertion t(21;8)(q22;q24q22) in tetraploidy responded poorly to chemotherapy and achieved molecular remission with difficultly. Data from patients in this group indicated that near-triploidy/tetraploidy acute leukemia has poor prognosis and new therapy is urgently needed.

Is fluorescence in-situ hybridization sufficient in patients with myelodysplastic syndromes and insufficient cytogenetic testing?

Chromosome banding analysis (CBA) in myelodysplastic syndromes (MDS) remains the ‘gold standard’ for identification of chromosomal abnormalities, while interphase fluorescence in-situ hybridization (I-FISH) is mainly used to complement CBA. This study, retrospectively, evaluated CBA and I-FISH results in 600 patients with suspected MDS and determined the effect of CBA/FISH reallocation on IPSS-R. Our result demonstrated that in 7/586 (1.2%) patients with satisfactory karyotype, I-FISH provided additional information. In 25/453 (5.5%) of the patients with normal I-FISH, CBA detected chromosomal abnormalities, and in 68/147 (46%) of the patients with abnormal I-FISH, CBA detected additional chromosomal aberrations. When 5q- aberration was alone or accompanied by additional abnormalities by I-FISH, CBA revealed a complex karyotype (16/25;64%, 35/43;81%, respectively). Our results suggest that in cases of karyotype failure, if I-FISH is used alone, patients are at risk of being misclassified into the wrong cytogenetic risk groups and a repeat sample for CBA should be attempted.

Genetic Diagnosis of Chromosomal Congenital Anomalies in Albanian Pediatric Patients by Array CGH.

AIM:The aim of our study was to identify chromosomal imbalances by whole-genome microarray-based comparative genomic hybridization (array CGH) in DNA samples of children in which karyotype results cannot be obtained. The present paper describes the first Albanian experience of an array CGH application.MATERIAL AND METHODS:The cohort included seven children with developmental delay or intellectual disability, facial dysmorphism and congenital anomalies according to clinical criteria, suggestive of chromosomal anomalies. The age range was from newborn to five years old. The cytogenetic analysis determined by a standard method of G-banding according to the International System for Human Cytogenetic Nomenclature (ISCN 2005) was performed for all our patients, while array CGH was performed on genomic DNA isolated from the blood of 7 cases.RESULTS:Among the seven patients analysed with array CGH, three patients resulted in duplication and one deletion, one patient with a microdeletion and three patients with duplication. Array CGH facilitated the recognition of submicroscopic deletions and duplications as risk factors for genetic diagnosis in all our patients.CONCLUSIONS:Our case series with congenital chromosomal anomalies confirms the high diagnostic value of the method, as suggested by previous studies. The technique must be available also in less developed countries, to significantly improve the genetic diagnosis of paediatric patients with developmental delay or intellectual disability, congenital anomalies and dysmorphic features. The identification of chromosomal abnormalities in these patients and the genetic counselling will provide family members with an explanation for their child’s developmental disability or birth defect, allowing better information about recurrence risks, and permit the anticipation of certain medical problems that require intervention.

2 - Development of a Clinical Grade Interpretive Tool for Neoplastic Genomic Microarray Testing

The identification of chromosomal abnormalities in solid tumor and hematologic malignancies is important for disease diagnosis, prognosis, progression, and therapeutic decision making. The recent application of a range of powerful molecular technologies including chromosomal microarray and next generation sequencing has dramatically increased the resolution of clinical genomic testing, leading to increased precision in the evaluation of the cancer genome. In the era of complex tumor genomics, a comprehensive and clinically-vetted knowledge base is critical to providing efficient, accurate and informative clinical interpretations. Although several public databases/resources are available, comprehensive clinical-grade resources directly facilitating interpretation and reporting of neoplastic microarray cases are still lacking. To achieve this goal, the Mayo Clinic Cytogenetics Laboratory is manually assembling and curating a comprehensive knowledge base of specific genes and genomic regions of clinical relevance, including a pan-cancer gene list and disease-specific gene lists for major groups of solid tumors and hematologic malignancies. Here we describe our processes, data sources, and annotation conventions. We also describe how we utilize Affymetrix Extensible Data (AED) files to visualize our curated gene lists alongside microarray findings, which facilitates scrutiny of relevant critical regions and rapid recognition of clinical significance. Using these newly created cancer interpretive tools we have built thus far, we have successfully provided efficient, accurate and informative interpretation of neoplastic microarray cases. We hope to share our experience with the CGC group and encourage community sharing of resources to facilitate best practices in neoplastic genomic microarray testing.

Identification Of Chromosomal Abnormalities By Microarray-Based Genomic Profiling As Compared To Karyotyping In Patients With Low and Intermediate-1 Risk Myelodysplastic Syndromes Within a Prospective Clinical Trial: A Study On Behalf Of The HOVON89 Study Group

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal hematopoietic disorders, characterized by ineffective hematopoiesis resulting in cytopenias and a highly variable clinical course. Cytogenetics are routinely used as one of the diagnostic, prognostic and therapeutic markers in the clinical management of MDS (Greenberg et al. Blood 120:2454,2012). Although karyotyping is generally considered as the gold standard in the cytogenetic characterization of MDS, 40-60% of the patients exhibit a normal karyotype. Intrinsically, the resolution of karyotyping is limited by its capacity to detect only those copy number changes that are microscopically visible (5-10 Mb in size). In contrast, microarray-based genomic profiling analyses allow a genome-wide detection of copy number alterations (CNAs), down to 100 kb in size, and regions of copy neutral loss of heterozygosity (CNLOH). Such analyses also overcome some of the other major limitations of karyotyping such as low success rate due to inadequate metaphase yield and/or poor banding quality. We have compared karyotyping and fluorescence in situ hybridization (FISH) with microarray-based genomic profiling with respect to the detection yield for genetic abnormalities in bone marrow samples from lower risk MDS patients.We used the HOVON89 study-cohort, a prospective phase II randomized multicenter study to assess the efficacy of lenalidomide with or without erythropoietin and granulocyte-colony stimulating factor in patients with low/intermediate-1 risk MDS; www.trialregister.nl; NTR1825; EudraCT nr.: 2008-002195-10. Inclusion target of the study is 200 low/intermediate-1 risk MDS patients (134 enrolled, inclusion ongoing). Data regarding cytogenetics, FISH and microarray were obtained in a fully blinded fashion for 68 MDS patients. For microarray-based genomic profiling we used the recently launched high resolution CytoScan HD Array (Affymetrix) platform. The following interpretation criteria were applied: (i) the threshold for CNAs was set at >5 Mb, (ii) inclusion of <5 Mb CNAs segments that coincide with known cancer genes as reported on www.sanger.ac.uk and (iii) the threshold for CNLOH was set at >10 Mb and to telomere. Karyotyping and interphase FISH were performed using standard cytogenetic methods. In all 4 patients where karyotyping revealed no metaphases interphase FISH was performed.Thirty-six of the 68 (53%) MDS patients had an abnormal microarray profile. Of interest, in 13 of these 36 patients no abnormalities were observed by karyotyping and/or FISH. All these abnormalities observed by microarray only, involved focal <5 Mb CNAs (containing e.g. the TET2, RUNX1 and DNMT3A genes) and regions of CNLOH (coinciding with 1p, 2p, 4q, 7q, 11p, 11q, 12q, 14q and 18q), which are all out of the scope of karyotyping and FISH. All CNAs identified by karyotyping and FISH were also observed by microarray-based genomic profiling, including a case with loss of 5q in 5% of the cells and loss of 7q in 9% of the cells as observed by interphase FISH and another case with loss of 5q in 3 of 20 the analyzed metaphases by karyotyping. These observations demonstrate the high sensitivity of the CytoScan HD array platform for the identification of CNAs in (small) subclones. As expected balanced translocations such as t(3;3)(q21;q26) and t(2;14)(q37;q22) present in 2 of the patients in our cohort were not identified by microarray-based genomic profiling. This study will be extended to all patients to be included in the HOVON89 trial.In conclusion, we demonstrate that in the present cohort of 68 patients, microarray-based genomic profiling allows the identification of almost all copy number abnormalities also observed by karyotyping and FISH. In addition, we show that microarray-based genomic profiling allows the detection of potential prognostic relevant abnormalities (focal CNAs and CNLOH) which would have remained undetected by karyotyping and FISH. The predictive and/or prognostic value of these novel CNAs and CNLOH will be evaluated within the ongoing prospective clinical HOVON89 trial in lower risk MDS. Disclosures:No relevant conflicts of interest to declare.

Identification of Chromosome Abnormalities in Subtelomeric Regions Using Multiplex Ligation Dependent Probe Amplification (MLPA) Technique in 100 Iranian Patients With Idiopathic Mental Retardation

BackgroundMental retardation/Developmental delay (MR/DD) is present in 1 - 3% of the general population (1, 2). MR is defined as a significant impairment of both cognitive (IQ < 70) and social adaptive functions, with onset before 18 years of age.ObjectivesThe purpose was to determine the results of subtelomeric screening by the Multiplex Ligation Dependent Probe Amplification (MLPA) Technique in 100 selected patients with idiopathic mental retardation (IMR) in Iran.Materials and MethodsA number of 100 patients with IMR, normal karyotypes and negative fragile-X and metabolic tests were screened for subtelomeric abnormalities using MLPA technique.ResultsNine of 100 patients showed subtelomeric abnormalities with at least one of the two MLPA kits. Deletion in a single region was found in 3 patients, and in two different subtelomeric regions in 1 patient. Duplication was only single and was present in 2 patients. Three patients were found to have both a deletion and duplication.MLPA testing in the parental samples of 7 patients which was accessible showed that 4 patients were de novo, 2 patients had inherited from a clinically normal mother, and one had inherited from a clinically normal father. Screening with the two MLPA kits (SALSA P036 and SALSA P070) proved abnormality in only five of the 9 patients.ConclusionsSo, the prevalence rate of abnormal subtelomeres using MLPA technique in patients with idiopathic MR in our study was 5 - 9%, the higher limit referring to the positive results of one of the two MLPA kits, and the lower limit representing the results of positive double-checking with the two MLPA kits.

Design and Feasibility of a Novel, Rapid, and Simple Fluorescence 26-Plex RT-PCR Assay for Simultaneous Detection of 24 Fusion Transcripts in Adult Acute Myeloid Leukemia

Identification of chromosomal abnormalities is mandatory for classification of acute myeloid leukemia (AML), and the abnormalities have to be determined quickly, to allow patient enrollment in multicenter protocols and/or for selecting therapeutic strategies. Rapid AML molecular diagnosis is often difficult to achieve, however, because it is based on numerous different RT-PCR protocols. We developed a new RT-PCR method, one that does not require a nested step, to simultaneously detect all AML fusion transcripts from six major recurrent translocations found in adults: t(15;17)(q22;q12), inv(16)(p13.1q22) [t(16;16)(p13.1;q22)], t(8;21)(q22;q22), t(6;9)(p23;q34), t(9;22)(q34;q11), and t(10;11)(p13;q14). Specific primers for RT-PCR detection of the 24 fusion transcripts, along with two transcripts for controls, were designed for this 26-plex RT-PCR. Each PCR product had a different size and was separated by capillary electrophoresis. We also designed a multiplex positive control with 24 chimeric RNAs, corresponding to all chimeric RNAs tested. Compared with classical molecular biology protocols and cytogenetic analyses used as reference standards, results of the 26-plex RT-PCR method were concordant in all 204 (100%) cases of adult AML tested. Results were obtained in less than 24 hours. Because of the multiplex positive control, interpretation of the peaks was very easy, without any ambiguity. The tumor cell detection threshold was 1.5%.

Segmentation of Overlapped and Touching Human Chromosome images

Chromosomes are essential genomic information carriers. The identification of chromosome abnormalities is an essential part of diagnosis and treatment of genetic disorders such as chromosomal syndromes and many types of cancer. Currently available cytogenetic imaging software is designed to classify only normal chromosomes. The automation of chromosome analysis is involving segmentation of chromosomes and classification into 24 groups. Segmentation of the overlapped chromosomes is a major step toward the realization of homolog classification. Resolving chromosome overlaps is an unsolved problem in automated chromosome analysis. Current systems for automatic chromosome classification are mostly interactive and require human intervention. In this paper, an automatic procedure is proposed to obtain the separated chromosomes. The separations of overlapped and touching chromosomes are obtained by finding the intersecting (concave and convex) points with the help of Novel algorithm. The intersecting points are located on contour of the image and then the curvature function is used to find out concave points. Then the possible separation lines are plotted by using all concave points and finally construct the hypotheses for possible separation lines between concave points. The segmentation is carried out by means of a curvature function scheme, which proved to be successful.

Identification of chromosome abnormalities in screening of a family with manic depression and psoriasis: Predisposition to aneuploidy

Cytogenetic analysis is an important stage in understanding the genetic background of manic depression (MD), and may provide a valuable clue to the identification of target loci and successful search for major genes. In order to identify chromosomal regions we aimed to detect the relationships between chromosomal aberrations (CAs) and immunological markers in a family with MD and psoriasis. We used the cell cultivation and conventional G-banding. We found predominantly numerical aberrations. The most common aneuploidy was chromosome 8, followed by chromosome 22, 21, 15, X and Y. However, structural aberrations consisted of duplications, deletions, translocations and breaks, with a focus on: loci on del(1)(q12–q23), del(1)(q21.1–q24), del(1)(q21.1–q23), del(10)(p11.2-pter), der(2)t(2;4)(p25;p12), t(2;22)(p14;p13), t(19;Y)? and dup(10)(q26). The susceptibility genes of MD or psoriasis may be located on these loci. Numerical sex CAs included 4(5.8%) with 45,X, 3(4.3%) with 47,XXY, and 4(5.8%) with structural chromosome X; del(X)(q13); del(X)(p11-pter) del(X)(q21.3) and inv(Y)(q11.2). We also conducted an immunological study. According results of this study, the percentage of CD2+, CD4+ and CD8+ lymphocytes of the father were significantly higher, whereas CD4+ lymphocytes were decreased in the mother, when compared the healthy persons. The percentage of CD4 level of the son was decreased, whereas CD8+ lymphocytes were higher. The CD4/CD8 ratio of the father and the son was found to be significantly high. These results may suggest that MD and psoriasis have a significant impact on both genetic and immunological parameters.

725: A retrospective study of BACs-on-Beads (BoBs) technology for identification of chromosome abnormalities compared with QF-PCR and karyotyping in prenatal diagnosis

sion was performed to control for confounding variables. RESULTS: 309 women had CVS performed and also had pregnancy outcomes available in our database. Absence of villi buds was associated with preterm birth (p .001) and GDM (p .005). 92.6% of samples had composite scores of 2-6. High composite score (7-9) was associated with gestational hypertension (p 0.038) and 5 minute Apgar less than 7 (p 0.032). Both high (7-9) and low (0-1) composite scores were associated with preterm delivery (p 0.002). Low composite score was associated with GDM (p 0.003). Gestational age at procedure was associated with morphology (p 0.00). The association of high or low composite morphology score with these outcomes remained significant in the logistic regression analysis. CONCLUSION: Morphologic characteristics of chorionic villi already demonstrate abnormal features in the late first trimester in some pregnancies destined for poorer obstetric outcomes. Identifying the underlying molecular etiology responsible for underor overdeveloped chorionic villi may aid in a greater understanding of the molecular mechanisms leading to these adverse pregnancy outcomes.

Trends in cytogenetic testing and identification of chromosomal abnormalities among pregnancies and children with birth defects, metropolitan Atlanta, 1968–2005

The purpose of this study was to examine changes in the use of cytogenetic testing and identification of chromosomal abnormalities among pregnancies and children with birth defects. Utilizing data from 1968 to 2005 from the Metropolitan Atlanta Congenital Defects Program, we analyzed trends in the frequency and timing (prenatal or postnatal) of cytogenetic testing and the prevalence of recognized chromosome abnormalities among pregnancies and children with birth defects (n = 51,424). Cytogenetic testing of pregnancies and children with birth defects increased from 7.2% in 1968 to 25.0% in 2005, as did the identification of chromosomal abnormalities (2.2% in 1968 to 6.8% in 2005). The use of prenatal cytogenetic testing decreased from 1996 to 2005 among women aged ≥35 years. Identification of chromosomal abnormalities in pregnancies and children with birth defects increased from 1968 to 2005, possibly due to increased testing, improved diagnostic techniques, or increasing maternal age. The decline in prenatal cytogenetic testing observed among mothers aged ≥35 years may be related to the availability of improved prenatal screening techniques, resulting in a reduction in the utilization of invasive diagnostic tests.

Identification of chromosome abnormalities in the horse using a panel of chromosome-specific painting probes generated by microdissection

Fluorescent in situ hybridisation (FISH) using a panel of molecular probes for all chromosome pairs obtained by chromosome microdissection of the domestic horse ( Equus caballus ) was used to diagnose karyotype abnormalities in 35 horses (32 mares, 2 stallions and 1 intersex), which were selected for the study due to infertility (23 horses), reduced fertility (10 horses) and developmental anomalies (2 horses). The use of the FISH technique with probes for each horse chromosome pair enabled the diagnosis of many different chromosome aberrations in this population. Among the horses analysed, 21 animals had normal karyotype - 64,XX (19 mares) and 64,XY (2 stallions). Fourteen animals, constituting 40% of the population studied, showed the following chromosome abnormalities: 63,X (1 mare); 63,X/64,XX (6 mares); 63,X/64,XX/65,XXX (3 mares); 63,X/65,XXX (1 mare); 64,XX/65,XX+Xp (1 mare); 63,X/64,XX/65,XX+Xq (1 mare), and 63,X/64,XX/65,XX+delY (1 intersex). When only the mares studied because of complete infertility were taken into consideration, this proportion exceeded 56%. Due to the increased frequency of the above-mentioned aberrations in the mosaic form of two or more lines, it was necessary to analyse a large number (100-300) of metaphase spreads. The use of specific molecular probes obtained by chromosome microdissection made these diagnoses much easier.

Automated Identification of Chromosome Segments Involved in Translocations by Combining Spectral Karyotyping and Banding Analysis

The identification of chromosome abnormalities is an essential part of diagnosis and treatment of genetic disorders such as chromosomal syndromes and many types of cancer. Modern cytogenetic imaging techniques have improved the study of chromosome aberrations but they are most often used as adjuncts to traditional G-banded karyotype analysis. Molecular cytogenetic techniques such as comparative genomic hybridization, multicolor fluorescence <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</i> <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">situ</i> hybridization, and spectral karyotyping (SKY) are able to detect chromosome copy number changes and complex structural aberrations in cancers, particularly in hematological malignancies and solid tumors. However, banded chromosome analysis is essential to distinguish between normal and abnormal chromosomes. Currently available cytogenetic imaging software is designed to classify only normal chromosomes. The identification of the banded regions involved in the abnormal chromosomes is done manually. In this paper, we propose an algorithm to automate the banding analysis of abnormal chromosomes by comparing the information obtained by SKY for precise identification of translocation break points. Our algorithm is based on the dynamic time warping method in order to overcome the problems due to the nonrigid nature of chromosomes. The method has been implemented and successfully applied to detect chromosome translocations, deletions, and duplications in cell lines derived from solid tumors.