Application Of Karyotyping And Flourescent In Situ Hybridisation In Detection Of Klinefelter Syndrome

Introduction: Klinefelter Syndrome is one of most common sex chromosomal abnormality in males with incidenceof 1 in 600 live births. Fluorescence in situ hybridization (FISH) is a powerful molecular cytogenetic techniquewhich allows rapid detection of aneuploidies on interphase cells and metaphase spreads along with conventionalGTG banding technique.Aims and objectives: To evaluate application of karyotyping and FISH as important diagnostic tool in diagnosisKlinefelter Syndrome.Materials and Methods: A retrospective study was conducted on 44 patients who were referred for karyotypingand counselling with suspected Klinefelter Syndrome and hypogonadism to Division of Human Genetics,Department of Anatomy, St. John’s Medical College, Bangalore from January 2014 to October 2017. Chromosomalpreparations were done using the peripheral lymphocyte culture method followed by GTG banding technique,automated photography and karyotyping.FISH was performed with dual colour X/Y probes once abnormality was detected using GTG banding technique.Results: Out of 44 patients, 9 had typical karyotype of Klinefelter syndrome (47,XXY) and Four had variants ofKlinefelter syndromeConclusion: We can conclude that cytogenetic analysis forms important investigation in diagnosis , treatmentand fertility status in patients with Klinefelter syndrome.

Fluorescence In Situ Hybridization on Enriched CD138-Positive Cells in Plasma Cell Myeloma.

To validate plasma cell enrichment technique for improving the detection of cytogenetic abnormalities in the Plasma cell myeloma (PCM)/multiple myeloma (MM). We compared the abnormality detection rate for overnight unstimulated bone marrow cultures to that for the plasma cell enriched fractions obtained with the use of CD138-coated immunomagnetic beads. Average enrichment factor (EF) was 11. One or more abnormalities were detected in 90% of enriched samples vs. 65% of non-enriched samples, thus resulting in a significantly higher detection rate of total cytogenetic abnormalities in enriched plasma cells (p=0.0038). Additional findings of RB1 deletion, TP53-, 1p-, 1q+ and IGH@ rearrangement seen in the 25% of enriched samples could contribute to the altered risk in the patient. One of the three cases with plasma cells as low as 1% by morphology was positive for a residual disease marker in the enriched sample and negative in the non-enriched sample. The plasma cell enrichment technique increased the detection rate of diagnostic and prognostic markers and is a very sensitive method for detecting minimal residual disease.

Gene Mapping: Basics, Techniques and Significance.

Watson says, "Like the system of interstate highways spanning our country, the map of the human genome will be completed stretch by stretch". It may be possible to use genetic information to diagnose the disease accurately and to predict a patient's likely response to a particular medicine or treatment. For whole genome mapping development and application of mapping, sequencing and computational tools are very essential and also linkage, physical and sequence maps are required to put the information together. For most genome mapping projects involve markers consisting of a unique site in the genome and should be independent of any particular experimental resource. For mapping purpose the DNA and RNA identification is essential. These genes are identified by hybridizing DNA clones against Northern blot, cDNA libraries, Zoo blot, Western blot and Southern blot of genomic DNA digested with rare cutter restriction endonuclease. The various experimental studies of gene mapping have extended our understanding of the genetics. This has allowed the investigators to detect a particular gene, which is responsible for the disease. Recent studies have shown the various effective and scientific gene mapping techniques and gene identification methods, which are helpful to diagnose a particular disease. It is easy for the doctor to give right medicine to the right patient to cure the disease when he can identify the defective gene responsible for disease. This article reviews the details of identification techniques of genes, gene mapping with broad applications.

Diagnóstico genético preimplantacional: análisis de aneuploidías únicas / Preimplantational genetic diagnosis: single aneuploidies analysis

Introducción: De las causas más conocidas en cuanto a la falta del éxito en el embarazo con tratamientos de reproducción asistida son aquellas relacionadas a las aneuploidías cromosómicas presentes en los embriones. El diagnóstico genético preimplantacional (PGD) es una técnica empleada en reproducción asistida para detectar estas anomalías, seleccionando aquellos que sean cromosómicamente normales, para luego transferirlos al útero de la paciente. Los embriones con aneuploidías únicas podrían tener la capacidad de sobrevivir y lograr la implantación, y por lo tanto, sin diagnóstico previo, estas podrían pasar desapercibidas. Objetivos: Determinar la incidencia de aneuploidías únicas en embriones de buena calidad embrionaria en el día 3 de desarrollo hasta blastocisto. Diseño: Estadístico y experimental. Instituciones: Reprogenetics Latinoamérica y Centro de Reproducción asistida, de la Clínica Concebir. Material Biológico: Muestras de biopsia embrionaria. Metodología: Análisis comparativo de resultados a partir de la evaluación de cada muestra obtenida por biopsia en el día tercero y día quinto de desarrollo embrionario, realizando el PGD por hibridación in situ (FISH) y genómica comparada (aCGH), respectivamente. Resultados: El 62,9% de embriones que presentaron monosomías únicas al tercer día de desarrollo embrionario resultaron ser de 8 células. Pero cuando se evaluó por aCGH en día cinco, 42,3% resultó anormal, y de estos 37,5% perteneció al estadio de 8 células. El índice de monosomías únicas en blastocisto resultó ser 57,9% de un total de 84,2% de aneuploidías únicas. Conclusiones: Los embriones de 8 células en el tercer día de desarrollo embrionario son los más probables de llegar al estadio de blastocisto, así como presentar aneuploidías únicas.

Background: Known causes of unsuccessful pregnancy in couples undergoing assisted reproduction treatment include embryo aneuploidies. Preimplantation genetic diagnosis (PGD) is a technique used in assisted reproduction in order to detect these abnormalities, select embryos chromosomally normal and subsequently transfer to the patients’ uterus. Embryos with single aneuploidies may have the ability to survive and achieve unnoticed implantation. Objectives: To determine incidence of single aneuploidies in good quality embryos in third day of development to blastocyst. Design: Statistical and experimental study. Setting: Reprogenetics Latin-America and Assisted Reproduction Center - Concebir. Biologic material: Samples of embryo biopsies. Methods: Comparative analysis of results from evaluation of each sample obtained by embryo biopsy on the third and fifth days of embryonic development, performing PGD by respectively in situ hybridization (FISH) and comparative genomics (aCGH). Results: On third day of embryonic development 62.9% of embryos with single monosomy had 8-cell morphology. Though when evaluated by aCGH in the blastocyst stage 42.3% were abnormal and 37.5% of these belonged to the 8-cell stage. Single monosomies index in the blastocyst stage was 57.9% in 84.2% of single aneuploidies. Conclusions: Eight-cell embryos on the third day of embryonic development are most likely to reach blastocyst stage and have single aneuploidies.

Another small supernumerary marker chromosome derived from chromosome 9 in a Klinefelter patient / Otro cromosoma marcador supernumerario pequeño derivado del cromosoma 9 en un paciente con el síndrome de Klinefelter

Marker chromosomes are very rare in Klinefelter patients and phenotypic findings are related to the affected chromosomal region. The phenotypic effects of small supernumerary marker chromosomes (sSMC) range from multiple malformations/mental retardation to no effect (ie a normal phenotype). This wide spectrum of phenotypes is due to the origin, structure and gene content of the marker chromosome. The first Klinefelter case with sSMC 9 was published by Liehr et al in 2005. The present case was referred for chromosomal analysis because of dysmorphic features, speech delay and mild mental retardation. Conventional cytogenetic analysis revealed the 47 XXY karyotype in 17 metaphases and the 48 XXY + marker karyotype in eight metaphases. Fluorescence in situ hybridization (FISH) analysis to identify the marker chromosome was performed using the LSI p16 (9p21) Spectrum Orange/CEP 9 SpectrumGreen Probe (Vysis CDKN2A/CEP 9 FISH Probe) and partial trisomy 9 mosaicism was confirmed in this patient. To our knowledge, this is the second case of Klinefelter syndrome with a small supernumerary marker chromosome derived from chromosome 9.

Los cromosomas marcadores son muy raros en los pacientes de Klinefelter, y los hallazgos fenotípicos se relacionan con la región cromosomática afectada. Los efectos fenotípicos de los cromosomas marcadores supernumerarios pequeños (sSMC) van desde el retraso mental y las malformaciones múltiples hasta la ausencia total de efectos (es decir, un fenotipo normal). Este amplio espectro de fenotipos se debe al origen, estructura y contenido del gen del cromosoma marcador. El primer caso de síntoma Klinefelter con sSMC 9 fue publicado por Liehr et al en 2005. El caso presente fue remitido para análisis cromosomático debido a rasgos dismórficos, retraso del habla, y retardo mental ligero. El análisis citogenético convencional reveló el cariotipo 47 XXY en 17 metafases y el cariotipo marcador 48 XXY+ en ocho metafases. El análisis mediante hibridación fluorescente in situ (FISH) para identificar el cromosoma marcador se realizó usando la sonda LSI p16 (9p21) Spectrum Orange/CEP 9 SpectrumGreen Probe (Vysis CDKN2A/CEP 9 FISH Probe). Un mosaicismo de trisomía 9 parcial fue confirmado en este paciente. Hasta donde sabemos, éste es el segundo caso de síndrome de Klinefelter con un cromosoma marcador supernumerario pequeño derivado del cromosoma 9.

Diagnóstico prenatal citogenético mediante la hibridación in situ con fluorescencia / Cytogenetic prenatal diagnosis by means of in situ hybridization with fluorescence

La utilización de la técnica de hibridación in situ con fluorescencia aplicada al diagnóstico prenatal citogenético es una vía rápida para establecer un nexo entre los genes y los cromosomas sin necesidad de realizar cultivos celulares, permitiendo la detección de anomalías cromosómicas en células en interfase. El objetivo del presente trabajo fue evaluar los resultados obtenidos en la introducción de este método para el diagnóstico prenatal de aneuploidías en embarazos de alto riesgo. Se examinaron 40 casos prenatales de alto riesgo por la técnica de hibridación in situ, se obtuvieron resultados satisfactorios en 34. Se corroboró con el resultado obtenido de la citogenética convencional en el 97 por ciento de los casos. Se realizó el diagnóstico de aneuploidías de los cromosomas 18, 21 y 13, el 80 por ciento de los núcleos examinados, presentó 3 señales. En los casos normales no existieron discrepancias con la citogenética respecto a los cromosomas sexuales, el número de cromosomas autosómicos (21,13 y 18) y los marcajes observados por FISH. Esta técnica debe ser aplicada en casos de alto riego de aneuploidías de los cromosomas 21, 13, 18 y X, casos con elevada ansiedad materna, y/o cuando una determinada situación clínica así lo demande. Esta técnica debe ser complementada mediante el examen cromosómico de las células fetales

Fluorescence in situ hybridization applied to the cytogenetic prenatal diagnosis is a rapid way to stablish a nexus between genes and chromosomes without celular culture and allows detection of chromosomal abnormalities on interphase cells. The aim of the present study was to evaluate this method as a tool in prenatal diagnosis of aneuploidies in high risk pregnancies. Prenatal diagnosis was carried out in 40 high-risk pregnancies using fluorescence in situ hybridization, 34 had successuful results. The 97 percent the cases were confirmed by conventional cytogenetic results. The diagnosis of 18, 21 and 13 chromosome aneuploidies showed three hybridization signals in 80 percent of the scored nuclei. The results of fluorescence in situ hybridization were in conformity with the results of cytogenetic analysis in all the normal cases (sex and autosomic chromosomes). This technique should be applied in high risk cases of chromosomes aneuploidies (21,18, 13 and X), high maternal anxiety, or when significant clinical situation is present. It should be employed as an adjunctive tool to the examination of fetal chromosomes

Evaluation of HER-2/neu status in breast cancer specimens using immunohistochemistry (IHC) & fluorescence in-situ hybridization (FISH) assay.

Background & objectives: Fluorescence in situ hybridization (FISH) is increasingly being recognized as the most accurate and predictive test for HER2/neu gene amplification and response to therapy in breast cancer. In the present study we investigated HER-2/neu gene amplification by FISH in breast carcinoma tissue specimens and compared the results with that of immunohistochemical (IHC) analysis. Methods: A total of 90 breast carcinoma tissue samples were used for immunohistochemical (IHC) and FISH analysis. IHC was performed by using mouse monoclonal antibody to the intracellular domain of HER-2/neu protein. Each slide was scored in a blinded fashion by two pathologists according to the manufacturer's recommended criteria. FISH analysis was performed on paraffin embedded breast tumour tissue sections. The polysomy for centromere 17 (Spec green signal) was read as green signals less than 4 as moderate polysomy, and more than 4 as highly polysomy. Results: Thirty of the 90 patients had negative results by IHC and FISH. Of the 28 patients with the score of 2+ by IHC, 20 were FISH positive for HER-2/neu gene amplification, three were FISH negative and five patients showed equivocal (1.8-2.2) results by FISH. These five cases were retested for IHC and FISH on different paraffin embedded tissue blocks, and all five were found positive for HER-2/neu gene amplification. Twenty five patients with the score of 3+ by IHC were FISH positive for HER-2/neu gene amplification (>2.2). Seven cases with the score of 3+ by IHC were FISH negative for HER-2/neu gene amplification (>2.2), and showed polysomy of chromosome number 17 high polysomy > 4. Interpretation & conclusions: Our results indicated that HER-2/neu status by FISH should be performed in all cases of breast tumour with a 2+ score by IHC. Cases demonstrating a 3+ score by IHC may be subjected to FISH to rule out polysomy of chromosome 17 which could be falsely interpreted as HER-2/neu overexpression by IHC analysis. There is also a need for establishing a clinically validated cut-off value for HER-2/neu FISH amplification against IHC which may be further compared and calibrated.

Expression of Survivin gene in human breast cancer and its clinical significance / 中华内分泌外科杂志

Ohjective To investigate the expression of Survivin gene in human breast cancer and its clinical significance.MethodsReal-time PCR technology and fluorescence in situ hybridization (FISH) technology were employed to detect the expression of Survivin gene in the following tissue samples:50 breast cancers in stage Ⅰ and Ⅱ,50 breast cancers in stage Ⅲ and Ⅳ,and the corresponding adjacent normal mammary tissues.The relationship of Survivin gene expression and several factors such as differentiation degree,invasion,lymph node metastasis,TNM stage was explored.ResultsThe positive expression rate of Survivin gene was 62％ and 78％ respectively detected by real-time PCR and FISH in breast cancer tissues.The overexpression of Survivin gene was positively correlated with TNM stage and lymph node metastasis.ConclusionsOverexpression of Survivin gene can be used as one of the parameters in early diagnosis and prognosis of human breast cancer.Selective gene therapy based on these gene expressions may be useful.

Multicolor fluorescence in situ hybridization analysis on rDNA and telomere of Isatis indigotica / 中草药

Objective: To investigate the physical location of 45S, 5S rDNA, and telomere sequences and analyze the karyotype of the metaphase chromosomes of Isatis indigotica. Methods: Multicolor fluorescence in situ hybridization (FISH) approach was used to detect the physical location of the above sequences. Results: One pair of 45S rDNA sites located on chromosome 4, one pair of 5S rDNA sites located on chromosome 5 and 14 pairs of telomere sites located at the ends of each chromosome in I. indigotica were detected. The karyotype formula is 2n = 2x = 14 = 10m (2SAT) + 4sm, which belongs to 2A karyotype. Conclusion: This research provides effective cytological markers for karyotype analysis and construction of a molecular cytogenetic map of I. indigotica.

Assessment of HER-2/neu status in breast cancer using fluorescence in situ hybridization & immunohistochemistry: Experience of a tertiary cancer referral centre in India.

Background & objective: Determination of HER2 status in breast cancer has become important to identify potential candidates for anti-HER2 therapy. In this study we compared fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) for the determination of HER2 status in breast cancer patients referred to a tertiary care referral centre. Methods: A total of 200 cases of invasive breast cancer were evaluated for HER2 status using IHC and FISH and results were compared. Results: The IHC 3+ (93.9%) and IHC negative (85.9%) cases showed good concordance with the corresponding FISH results; while 66.6 per cent of IHC 2+ cases showed gene amplification by FISH. In addition, hormone receptor expression and HER2 gene status showed a statistically significant inverse association (P<0.05). Interpretation & conclusion: These findings reaffirm IHC as a prudent first-step to screen tissue samples for HER2 status and to determine suitability for technically demanding FISH test and the dual coloured FISH as a gold standard for determination of HER2/neu status in IHC equivocal cases of breast carcinoma.

Fluorescence in situ hybridization for detection of bladder cancer / 国际外科学杂志

Objective To asses the value of fluorescence in situ hybridization (FISH) in diagnosis of transitional cell carcinoma of bladder in the urine using directly labeled DNA probes to the pericentromeric regions of chromosomes 3 , 7 and 17 and to the region of P16 tumor suppressor gene. Methods Chromosomal and gene abnormalities were detected using directly labeled DNA probes to the pericentromeric regions of chromosomes 3 , 7, and 17 and to the region of P16 tumor suppressor gene. The sensitivity of FISH and Cytology in diagnosing transitional cell carcinoma of bladder was also compared. Results The sensitivity of FISH and Cytology in diagnosing the disease was 85.5% and 34.2%, respectively. The sensitivity of FISH was prior to that of Cytology( P ＜0.05 ) and increased with increasing tumor pathologic grade but not clinical staging. Conclusions High sensitivity of FISH in diagnosing transitional cell carcinoma of bladder was obtained and it might be a potent method to diagnose bladder cancer in Chinese people in the future.

Chromosomal localization and molecular marker development of the lipopolysaccharide and beta-1,3-glucan binding protein gene in the Zhikong scallop Chlamys farreri (Jones et Preston) (Pectinoida, Pectinidae)

Zhikong scallop Chlamys farreri (Jones et Preston) is an economically important species in China. Understanding its immune system would be of great help in controlling diseases. In the present study, an important immunity-related gene, the Lipopolysaccharide and Beta-1,3-glucan Binding Protein (LGBP) gene, was located on C. farreri chromosomes by mapping several lgbp-containing BAC clones through fluorescence in situ hybridization (FISH). Through the localization of various BAC clones, it was shown that only one locus of this gene existed in the genome of C. farreri, and that this was located on the long arm of a pair of homologous chromosomes. Molecular markers, consisting of eight single nucleotide polymorphism (SNPs) markers and one insertion-deletion (indel), were developed from the LGBP gene. Indel marker testing in an F1 family revealed slightly distorted segregation (p = 0.0472). These markers can be used to map the LGBP gene to the linkage map and assign the linkage group to the corresponding chromosome. Segregation distortion of the indel marker indicated genes with deleterious alleles might exist in the surrounding region of the LGBP gene.

Preliminary data of preimplantation genetic diagnosis for aneuploidy screening using fluorescent in situ hybridization in Siriraj Hospital.

Objective: Preimplantation genetic diagnosis (PGD) is technique for detecting genetic diseases. Preimplantation genetic diagnosis for aneuploidy screening (PGD-AS) using fluorescent in situ hybridization (FISH) has been used worldwide including at Siriraj Hospital. The objective of this study was to comparethe pregnancy rate between a PGD-AS group with standard assisted reproductive techniques (ARTs) in Siriraj Hospital. Methods: Couples who requested PGD-AS underwent a standard ARTs process followed with blastomere biopsy for FISH analysis. The pregnancy rate was compared among the PGD-AS group and the control group. The control group was divided into 2 subgroups – all patients required ARTs subgroup and age ≥ 35 yrs. subgroup. Results: 6 stimulated cycles from 4 patients were performed in the PGD-AS group. The pregnancy rate per stimulated cycle in the PGD-AS group, control group and age ≥ 35 yrs group were 33.33%, 16.20% and 12.05% respectively. Moreover, the pregnancy rate per transferred cycles in the PGD-AS group, control group and age ≥ 35 yrs group were 40.00%, 21.02% and 13.17% respectively. Conclusion: PGD is an advanced method for detecting genetic defects. PGA-AS might increase the pregnancy rate.

Rapid prenatal diagnosis of chromosome aneuploidies in 943 uncultured amniotic fluid samples by fluorescence in situ hybridization (FISH)

PURPOSE: Fluorescence in situ hybridization (FISH) on uncultured amniotic fluid cells offers the opportunity for rapid screening of aneuploidies and has become an integral part of the current practice in many clinical cytogenetics laboratories. Here, we retrospectively analyzed the results of interphase FISH in 943 amniotic fluid samples and assessed the efficiency of FISH for rapid detection of aneuploidies. METHODS: Interphase FISH for chromosome 13, 18, and 21 was performed in 943 consecutive amniotic fluid samples for rapid diagnosis of aneuploidies referred from 2004 to 2006. Karyotypes from standard cytogenetic analysis were compared to the FISH results. RESULTS: A total of 45 chromosomal rearrangements (4.8%) were found after conventional cytogenetic analysis of the 943 amniotic fluid. After exclusion of known familiar chromosomal rearrangements and inversions (2.1%, 20/943), 2.7% (25/943) were found to have chromosomal abnormalities. Of this group, 0.7% (6/943) were chromosomal abnormalities not detectable by FISH and 2.0% (19/943) were numerical abnormalities detectable by FISH. All 14 cases of Down syndrome (Classic type, 13 cases; Robertsonian type, 1 case) and 5 cases of trisomy 18 were diagnosed and detected by FISH and there were no false-positive or -negative results (specificity and sensitivity=100%). CONCLUSION: The present study demonstrates that FISH can provide a rapid and sensitive clinical method for prenatal identification of chromosome aneuploidies. However, careful genetic counseling is essential to explain the limitations of FISH, including the inability to detect all chromosomal abnormalities and the possibilities of uninformative or false-negative results in some cases.

Application of rapid identification for Streptpcoccus mutans, Streptpcoccus sobrinus and Streptpcoccus sanguis in the native dental plaque biofilm by fluorescence in situ hybridization / 中华微生物学和免疫学杂志

Objective To examine Streptpcoccus mutans,Streptpcoccus sobrinus and Streptpcoccus sanguis in the early formation of native dental plaque biofilm. Methods An experimental dental plaque biofilm model in the oral cavity was established using enamel slabs. The spatial distribution of S. mutans, S.sobrinus and S. sanguis in the early colonization of dental plaque biofilms on the enamel surface was observed bv in situ, real-time and dynamic observations and optical sections utilizing confocal laser scanning microscopy(CLSM) and fluorescence in situ hybridization(FISH). The experiment data were analyzed with One-Way AVOVA, α=0.05 using SPSS11.5. Results Dental biofilm had a certain degree of thickness and various forms in three-dimensioned structure. The bacteria in the structure were sparse at the inner layers and the outer layers. In the middle layers the bacteria were closely compacted. There were many voids traversing from the outside of the biofilm to the enamel surface. At the initial stage of dental biofilm formation, the scanned average thickness of S. mutans,S. sobrinus and S. sanguis increased with time elapsing,the mean thicknesses of 1 h biofilms were 20.43 μm,11.50 μm and 14.76 μm,respectively,and those of 24 h were the thickest in terms of average level,the mean values were 70.25 μm,75.40 μm and 79.98 μm,respectively. Conclusion The fluorescence in situ hybridization combined with CLSM are thought to be convenient and sensitive to detect S. mutans, S. sobrinus and S. sanguis in the dental plaque biofilms.

Physical mapping of the 18S and 5S ribosomal genes in nine Characidae species (Teleostei, Characiformes)

Characidae is one of the largest fish families of the Neotropical region, and presenting a pronounced morphological variability, certainly does not constitute a monophyletic group. The cytogenetical data also show a large chromosomal variation and can provide important information for a better understanding of the relationships between the species of this group. 18S and 5S rDNA probes were used in the present study for the chromosomal mapping in different Characidae species from the São Francisco River (Astyanax lacustris, Astyanax scabripinnis, Hasemania nana, Piabina argentea, Orthospinus franciscensis, Serrapinnus heterodon, Serrapinnus piaba and Myleus micans) and Alto Paraná (Astyanax altiparanae) basins. Species with a single pair of chromosomes bearing the nucleolar organizing regions (NORs) were identified, as well as species with multiple NORs, up to a maximum of seven 18S rDNA sites. The number of 5S rDNA site was also not constant, varying from two to eight. The mapping of the ribosomal genes was useful for the characterization and differentiation of the analyzed species.

Rapid detection of aneuploidy using FISH in uncultured amniocytes for prenatal diagnosis : 8-year experience

PURPOSE: FISH is suggested as a useful tool for rapid detection of specific aneuploidy in uncultured amniocytes abnormality in interphase nucleus. In this study, we are going to share our experience using FISH in prenatal diagnosis and suggest the criteria for the diagnosis of aneuploidy by analyzing the results of FISH test. METHODS: From January, 1999 to May, 2006, 8,613 tests in amniotic fluids obtained from 7,893 pregnant women were performed by using FISH for prenatal diagnosis of trisomy 21, trisomy 18 and trisomy 13. The indications of chromosome study were a screen positive for Down syndrome or Edwards syndrome in maternal serum marker screening test and an advanced maternal age (> or =35 years old). RESULTS: We have the 8,502 informative results from 8,613 tests (98.7%) which is submitted our criteria and the sensitivity is 98.2%. CONCLUSION: FISH on uncultured amniocytes is a rapid, clinically useful tool for prenatal diagnosis, with informative specimens being highly accurate. But the limitation of FISH is both expensive and labor-intensive.

Satellite DNA sites in four species of the genus Astyanax (Teleostei, Characiformes)

Cytogenetic data about satellite DNA distribution in four Astyanax species (Characidae) from the Paraitinga river, Paraíba do Sul river basin, Brazil, are presented. In order to characterize the constitutive heterochromatin, C-banding, chromomycin A3 and DAPI fluorescence staining, as well as fluorescence in situ hybridization (FISH) with the satellite DNA As-51 probe were performed. A. scabripinnis and A. parahybae presented 2n = 50 and 2n = 48 chromosomes, respectively. The heterochromatin was located in the pericentromeric and terminal regions of many chromosomes, corresponding to GC-positive regions and to the As-51 satellite DNA in terminal regions. A. intermedius and A. giton, both with 2n = 50 chromosomes, showed little heterochromatin, mostly restricted to the terminal and pericentromeric regions of a few chromosomes. No GC-positive regions, neither any correspondence between the scarce heterochromatin of these species and the As-51 satellite DNA was observed. AT-positive blocks were not detected in any of the species studied. Based on these and other available data, the hypothesis that Astyanax represents a polyphyletic group is discussed.

Identification of marker chromosomes by reverse painting fluorescence in situ hybridization and comparative genomic hybridization / 대한산부인과학회지

OBJECTIVE: Although marker chromosome is defined as an abnormal chromosome in which no part can be identified, derivative chromosomes with structural abnormalities of unknown origin are also called as marker chromosomes conventionally. The clinical significance of a marker chromosome is determined according to the origin of marker chromosome. In this study reverse painting fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH) methods were employed to elucidate the origin of marker chromosomes in 5 clinical cases. METHODS: Reverse painting probes were generated from five copies of each marker chromosomes microdissected with micromanipulator, amplified with DOP-PCR, and labeled with fluorochromes. The probes were hybridized to normal metaphases. For CGH, normal control and patients' DNA were directly labeled with spectrum-red-dUTP and spectrum-green-dUTP by CGH nick translation kit, and hybridized to normal reference metaphases. The CGH images were captured with a computer controlled fluorescence microscope equipped with a CCD camera and analyzed by Cytovision workstation. RESULTS: Five marker chromosomes were identified as follows (1) derivative chromosome 15 inducing partial trisomy of 15pter->q21, (2) isochromosome of 18p causing 18p tetrasomy, (3) short arm of chromosome 5 causing 5p trisomy (4) small accessory chromosome originated from centromeric region of chromosome Xq11->q12 (5) der(17) with inverted duplication of the short arm of chromosome 17. In all cases the origin of each marker chromosomes were identified successfully with reverse painting FISH, and these results were concordant with the CGH profiles. CONCLUSION: Our results indicate that combined reverse painting FISH and CGH is a rapid, convinient and powerful tool to identify the origin of marker chromosomes and derivative chromosomes caused by various chromosome abnormalities such as translocation, duplication, deletion.

Improvement of Pregnancy Rate in Preimplantation Genetic Diagnosis with FISH Procedure by the Laboratory Optimization and Experiences / 대한불임학회지

OBJECTIVES: This study was performed to evaluate the laboratory system for successful PGD using fluorescence in situ hybridization (FISH) and the clinical outcome of PGD cycles in five years experiences. METHODS: A total of 181 PGD-FISH cycles of 106 couples were performed, and diagnosed chromosome normality in the preimplantation embryos. The laboratory and clinical data were classified by the following optimization steps, and statistically analyzed. Phase I: Blastomere biopsy with two kinds of pipettes, removal of cytoplasmic proteins without treatment of pepsin and culture of biopsied embryos with single medium; Phase II: Blatomere biopsy with single pipette, removal of cytoplasmic proteins with pepsin and culture of biopsied embryos with single medium; Phase III: Blastomere biopsy with single pipette, removal of cytoplasmic proteins with pepsin and culture of biopsied embryos with sequential media. RESULTS: A total of 3,209 oocytes were collected, and 83.8% (2,212/2,640) of fertilization rate was obtained by ICSI procedure. The successful blastomere biopsies were accomplished in 98.6% (2,043/2,071) of embryos, and the successful diagnosis rate of FISH was 94.7% (1,935/ 2,043) of blastomeres from overall data. Embryo transfers with normal embryos were conducted in 93.9% (170/181) of started cycles. There was no difference in the successful rate of biopsy and diagnosis among Phase I, II and III. However, the pregnancy rate per embryo transfer of Phase III (38.8%, 26/67) was significantly (p<0.05) higher than those of Phase I (13.9%, 5/36) and Phase II (14.9%, 10/67). CONCLUSIONS: The laboratory optimization and experience for the PGD with FISH procedure can increase the pregnancy rate to 38.8% in the human IVF-ET program. Our facility of PGD with FISH provides the great possibility to get a normal pregnancy for the concerned couples by chromosomal aberrations.