RESUMEN

OBJECTIVE: Schizophrenia, the most common major psychiatric disorder (or group of disorders), entails severe decline of higher functions, principally with alterations in cognitive functioning and reality perception. Both genetic and environmental factors are involved in its pathogenesis; however, its genetic background still needs to be clarified. The objective of the study was to reveal genetic markers associated with schizophrenia in the Bulgarian population. METHODS: We have conducted a genome-wide association study using 554 496 single nucleotide polymorphisms (SNPs) in 188 affected and 376 unaffected Bulgarian individuals. Subsequently, the 100 candidate SNPs that revealed the smallest P-values were further evaluated in an additional set of 99 case and 328 control samples. RESULTS: We found a significant association between schizophrenia and the intronic SNP rs7527939 in the HHAT gene (P-value of 6.49×10 with an odds ratio of 2.63, 95% confidence interval of 1.89-3.66). We also genotyped additional SNPs within a 58-kb linkage disequilibrium block surrounding the landmark SNP. CONCLUSION: We suggest rs7527939 to be the strongest indicator of susceptibility to schizophrenia in the Bulgarian population within the HHAT locus.

Asunto(s)

Aciltransferasas/genética , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Esquizofrenia/enzimología , Esquizofrenia/genética , Adulto , Anciano , Anciano de 80 o más Años , Bulgaria , Estudios de Casos y Controles , Cromosomas Humanos Par 1/genética , Femenino , Frecuencia de los Genes/genética , Genética de Población , Haplotipos/genética , Humanos , Desequilibrio de Ligamiento/genética , Masculino , Persona de Mediana Edad , Modelos Genéticos , Mapeo Físico de Cromosoma , Polimorfismo de Nucleótido Simple/genética , Reproducibilidad de los Resultados , Adulto Joven

RESUMEN

OBJECTIVE: Treatment of acute lymphoblastic leukemia (ALL) in adults focuses on the initial assessment of the prognostic relevant cytogenetic features as well as a response-guided therapy based on molecular data. We examined the importance of molecular-cytogenetic abnormalities for complete remission (CR) rates and the overall survival (OS) in adult ALLs. METHODS: Conventional cytogenetics and fluorescence in situ hybridization were performed on bone marrow cells from 33 newly-diagnosed ALL adults. Two karyotype categories [standard- risk group- normal karyotype, hyperdiplody and other structural aberrations, and high-risk group-t(11q23)/MLL, t(9;22)/bcr-abl, t(1;19), t(8;14), C-MYC and complex karyotype] and the biologically and clinically relevant ALL ploidy subgroups were prospectively defined. RESULTS: Chromosomal abnormalities were found in 52% of the cases with a high rate of poor-risk translocations - t(9;22), t(8q24), t(11q23), t(1;19). The total CR rate was 67% and the median time for achievement 2.33 months. Male sex, an age below 35 years and the absence of high risk translocations might have contributed to the high CR rates. Female patients, hyperdiplody, low white blood cells (WBC), and random cytogenetic aberrations had the longest OS. OS, 3- and 5-years survival periods were significantly shorter for poor-risk than standard risk group (p=.015, p=.001 and p=.005, respectively). CONCLUSION: This study emphasizes the lack of influence of cytogenetic aberrations on the CR and the time to achieve CR. However, our observations show that these aberrations are an independent prognostic factor in adult ALL - they allow predicting therapy resistance and the OS time after intense treatment.

RESUMEN

OBJECTIVE: The objective of this study was to assess the implication of copy number changes of epidermal growth factor receptor (EGFR) in lung cancer pathogenesis. MATERIALS AND METHODS: We used the highly reliable method of FISH, applied on tissue microarray (TMA), containing 306 lung tumors of different histological types, grades and tumor stage, in order to analyze the correlations between gene copy number changes and tumor phenotype. RESULTS: The frequency of EGFR copy number changes was 22.2%-2.8% amplifications and 19.4% gains. EGFR gains occurred more commonly in the squamous cell cancers (23.5%) than in adenocarcinomas (11.8%). Amplifications of EGFR were found only in the squamous cell cancers. Regarding cancer phenotype, there was a statistically significant correlation between EGFR copy number changes and histological grade (p = 0.001). No statistically significant relation could be observed with the metastatic spread of the tumors (lymphogenic and haematogenic) (p = 0.082 and p = 0.1, respectively). In our study EGFR could not be determined as a prognostic factor of survival (p = 0.6115). CONCLUSION: EGFR copy number changes could supplement the clinical significance of EGFR as a marker related to its pathogenesis and targeted therapy.

Asunto(s)

Receptores ErbB/genética , Dosificación de Gen , Neoplasias Pulmonares/genética , Adulto , Anciano , Receptores ErbB/fisiología , Femenino , Humanos , Hibridación Fluorescente in Situ , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Fenotipo , Pronóstico

RESUMEN

The development of molecular psychiatry in the last few decades identified a number of candidate genes that could be associated with schizophrenia. A great number of studies often result with controversial and non-conclusive outputs. However, it was determined that each of the implicated candidates would independently have a minor effect on the susceptibility to that disease. Herein we report results from our replication study for association using 255 Bulgarian patients with schizophrenia and schizoaffective disorder and 556 Bulgarian healthy controls. We have selected from the literatures 202 single nucleotide polymorphisms (SNPs) in 59 candidate genes, which previously were implicated in disease susceptibility, and we have genotyped them. Of the 183 SNPs successfully genotyped, only 1 SNP, rs6277 (C957T) in the DRD2 gene (P=0.0010, odds ratio=1.76), was considered to be significantly associated with schizophrenia after the replication study using independent sample sets. Our findings support one of the most widely considered hypotheses for schizophrenia etiology, the dopaminergic hypothesis.

Asunto(s)

Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple/genética , Receptores de Dopamina D2/genética , Esquizofrenia/genética , Población Blanca/genética , Adulto , Anciano , Anciano de 80 o más Años , Bulgaria , Estudios de Casos y Controles , Femenino , Pruebas Genéticas , Humanos , Masculino , Persona de Mediana Edad

RESUMEN

Several comparative genomic hybridization studies provide evidence for overrepresentation of the long arm of chromosome 20 in malignant melanoma. These studies also suggest that chromosome 20q contains genes that may contribute to melanoma pathogenesis. To refine the region of 20q amplification and to identify potential candidate genes involved in melanoma or even in melanoma progression from these regions, we combined fluorescence in-situ hybridization with MYBL2, ZNF217, CYP24 and STK6 specific probes (chromosomal region 20q13.1-q13.2) with high-throughput tissue microarray consisting of 280 primary melanomas and melanoma metastases. Low-level amplification ranging from 0.5 to 2.0% was detected for the tumor-related genes of interest. Higher frequencies of gain when compared with amplification were detected for MYBL2, ZNF217, CYP24 and STK6. Aneusomy of centromere 20 was observed in 29.9% of the analyzed tumors. A significantly higher frequency of ZNF217, CYP24 and STK6 total copy-number increase, as well as aneusomy of centromere 20, was found in the group of metastases when compared with the group of primary melanomas. Despite the technological advantage of fluorescence in-situ hybridization on tissue microarray, which allows refining regions of amplification, we were not able to recognize any of the MYBL2, ZNF217, CYP24 and STK6 genes as a particular relevant gene for melanoma tumorigenesis.

Asunto(s)

Mapeo Cromosómico , Cromosomas Humanos Par 20 , Melanoma/genética , Centrómero/genética , Femenino , Humanos , Hibridación Fluorescente in Situ , Masculino , Melanoma/parasitología , Análisis de Secuencia por Matrices de Oligonucleótidos

RESUMEN

OBJECTIVE: The objective was to evaluate the relationship between ploidy and chromatin status of human unfertilized oocytes/zygotes and infertility history, female age, and stimulation regimens. STUDY DESIGN: Two hundred and eighty-nine unfertilized oocytes and 63 zygotes were subjected to cytogenetic analysis: karyotyping for oocytes and fluorescent in situ hybridization (FISH) analysis for zygotes. Ploidy and chromosome/chromatin status were analyzed according to stimulation regimen, female age, and infertility history. The correlation coefficient was estimated and data were interpreted using a five-grade scale. RESULTS: Aneuploidy in karyotyped oocytes (19.7% hyperhaploidy, 18.8% hypohaploidy, and 6.3% haploid abnormal) was associated with chromosome fragmentation and lesions due to chromosome aging in culture. Premature chromosome condensation and cytoskeletal defects were significantly higher in unexplained infertility (34.7% and 52.9%, respectively; p<0.05). Chromatin quality was most important for successful ploidy analysis of zygotes. FISH analysis of abnormal zygotes elucidated genetic aspects of pronuclear number aberrations and raised questions about the current selection criteria. Abnormalities were found to correlate moderately with stimulation strategy and female age and significantly with infertility history. CONCLUSION: Genetic analysis of human oocytes and zygotes showed that poor chromatin quality and patient-related factors contribute to aneuploidy and pronuclear number aberrations.

Asunto(s)

Aneuploidia , Cromatina , Infertilidad/genética , Oocitos/citología , Inducción de la Ovulación , Cigoto/citología , Adulto , Factores de Edad , Técnicas de Cultivo de Célula , Aberraciones Cromosómicas , Femenino , Fertilización In Vitro , Humanos , Cariotipificación Espectral

RESUMEN

OBJECTIVE: To determine the frequency and type of chromosomal aberrations in different gestational age spontaneous abortions. STUDY DESIGN: In the study, 106 spontaneous abortions (SAs) were studied by comparative genomic hybridization. RESULTS: The frequency of detected chromosomal aberrations was 37.7%. Numerical chromosomal aberrations were disclosed in 82.5% of the aberrant cases, while structural chromosomal aberrations-in 17.5%. Highest frequency of aberrations was detected in the blighted ovum specimens (62.5%) compared to missed and second trimester SAs (respectively, 36.0% and 34.8%). With regard to structural aberrations, the difference in the frequencies between blighted ovum specimens and second trimester SAs nearly reached statistical significance (p=0.0847). However, due to the low number of blighted ovum specimens analyzed (n=8), this result should be interpreted with due caution. The most frequently affected chromosomal arms were Xp and Xq (13.7% of aberrant chromosomal arms, each), followed by 16p (8.4%), 16q (8.4%), 15q (4.2%) and 19q (4.2%). CONCLUSIONS: We describe for the first time a profile of chromosomal aberrations in SAs from different gestational ages, detected by CGH. Our results showed highest frequency of chromosome aberrations in blighted ovum specimens compared to other types of spontaneous abortions, higher rate of structural aberrations than reported before (17.5%) and some aberrations that so far were not found by CGH.

Asunto(s)

Aborto Espontáneo/genética , Aberraciones Cromosómicas/estadística & datos numéricos , Dermatoglifia del ADN/métodos , Edad Gestacional , Hibridación de Ácido Nucleico/métodos , Adulto , Aneuploidia , Cromosomas Humanos X , ADN/genética , Femenino , Humanos , Monosomía , Embarazo , Primer Trimestre del Embarazo/genética , Segundo Trimestre del Embarazo/genética

RESUMEN

Three types of defects of preimplantation embryogenesis contribute to the developmental arrest of cleaving human embryos: blastomere fragmentation, abnormal nuclear status and chromosomal disorders. Data concerning the relation and succession of these abnormalities during first mitotic cycles of the human zygote are controversial and mainly empirical at present. In this study we have performed simultaneous evaluation of blastomere fragmentation, nuclear apoptotic changes and the ploidy of four chromosomes (1, 5, 19 and X or 18, 21, X and Y) in 193 human embryos. Another group of 28 embryos was subjected to TUNEL for confirmation of apoptosis in blastomere nuclei. Nuclei with apoptotic chromatin were seen in nearly 1/10 of blastomeres of embryos with good morphology and in more than 1/5 of blastomeres of embryos with more than 20% fragmentation. The correct number of investigated chromosomes was registered in 85.2% of successfully tested embryos. Chromatin apoptotic changes are the only limiting factor for the success of chromosomal FISH tests. Nearly 1/2 of embryos with at least one apoptotic nucleus were chromosomally abnormal. For the embryos that contain only normal nuclei, the rate of ploid normality was more than 89%. The rate of euploidy was higher (66%) in embryos with a significant degree of cell fragmentation. Moderate cell fragmentation was not related to significant increase of chromatin and chromosomal disorders. In a substantial portion of abnormal blastomeres, chromatin damage preceded cell fragmentation. Nuclear destruction in human blastomeres was illustrated by fluorograms of different stages of chromatin lesions.

Asunto(s)

Aneuploidia , Apoptosis , Blastómeros/citología , División Celular/fisiología , Blastocisto , Núcleo Celular , Cromatina , Rotura Cromosómica , Trastornos de los Cromosomas , Embrión de Mamíferos/anomalías , Embrión de Mamíferos/anatomía & histología , Embrión de Mamíferos/citología , Desarrollo Embrionario/genética , Fertilización In Vitro , Humanos , Etiquetado Corte-Fin in Situ/métodos

RESUMEN

OBJECTIVES: The concept of multifactorial etiology of BEN anticipates that a combination of polymorphic gene variants and various environmental factors causes an increased risk for the disease. CYP enzymes play a key role in the metabolic activation of environmental chemicals and toxins. CYP3A enzymes are particularly relevant for xenobiotic metabolism because of their broad substrate specificity and abundant expression in the human liver, intestine, and kidney. Previous phenotyping analysis on CYP2D6 enzyme activity in BEN patients proposed a modifying effect of CYP2D6 gene variants on BEN risk, but it was not approved with molecular-genetic methods. The aim of the current case-control study was to compare the frequency of CYP2D6 and CYP3A5 polymorphisms, as well as one CYP3A4 promoter variant in BEN patients and controls in order to investigate a possible association between individual genetic variations in these genes and susceptibility to BEN. DESIGN AND METHODS: Ninety-six nonrelated Bulgarian BEN patients from endemic villages in the Vratza district and 112 healthy Bulgarians from nonendemic areas (controls) were genotyped. Identification of alleles was done by allele-specific PCR or by rapid-cycle amplification on the LightCycler, followed by sequence-specific detection. RESULTS: The UM, PM, and EM + IM genotype frequencies of CYP2D6 did not differ significantly between the two groups (P > 0.05). The CYP3A4*1B allele was only found in the heterozygous form, with allelic frequencies of 5.21% in the patients and 2.23% in the healthy individuals (P = 0.11). The CYP3A5*1 allele was more prevalent in BEN patients with a frequency of 9.38% compared to 5.36% in the controls and was associated with a higher risk for BEN (OR 2.41, 95% CI 1.09-5.33) (P = 0.02). CONCLUSIONS: Our results demonstrate that the CYP3A5*1 allele, previously reported as a marker for CYP3A5 expression in human kidney, is associated with increased risk for BEN, while CYP3A4*1B and CYP2D6 genotypes do not significantly modify the risk for the disease.

Asunto(s)

Nefropatía de los Balcanes/genética , Sistema Enzimático del Citocromo P-450/genética , Predisposición Genética a la Enfermedad , Polimorfismo Genético , Anciano , Estudios de Casos y Controles , Citocromo P-450 CYP2D6/genética , Citocromo P-450 CYP3A , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Reacción en Cadena de la Polimerasa , Factores de Riesgo

RESUMEN

BACKGROUND: Polymorphisms in NAD[P]H:quinone oxidoreductase (NQO1) and glutathione S-transferases (GSTs) have been reported to be associated with an increased risk for environmentally and/or occupationally induced renal and bladder cancers. Genetic factors related to chronic nephropathy and to urinary bladder or renal cancer development in Balkan endemic nephropathy (BEN) is unknown. In order to evaluate their possible role in BEN susceptibility, we determined the frequencies of NQO1 alleles *1, *2 and *3, as well as the GSTT1 and GSTM1 null genotypes in BEN patients and healthy subjects from a non-endemic region of Bulgaria. METHODS: The respective genotypes of 95 unrelated Bulgarian BEN patients and of 112 healthy individuals (control group) were determined by rapid cycle polymerase chain reaction (PCR) and detected with either SYBR green I fluorescent dye or melting curve analysis using allele specific probes. RESULTS: NQO1 genotyping showed a higher NQO1*2 allele frequency (23.68%) in BEN patients compared to controls (18.75%; p=0.219), while NQO1*3 allele frequencies were similar in both groups (2.63% in BEN patients vs. 2.23% in controls; p=0.791). The GSTT1 deficiencywas observed in 20% of BEN patients vs. 16.1% of controls (p=0.613). The GSTM1 null genotype was found in 45.3% of BEN patients vs. 51.8% of controls (p=0.674). There was no influence of NQO1 and GSTs genotypes found on BEN risk. CONCLUSIONS: Our results established that alleles NQO1*2 and NQO1*3, as well as lack of GSTT1 and GSTM1 did not influence the BEN risk. These findings provide novel information on the genetic heterogeneity in the healthy Bulgarian population.

Asunto(s)

Nefropatía de los Balcanes/genética , Frecuencia de los Genes , Glutatión Transferasa/genética , NAD(P)H Deshidrogenasa (Quinona)/genética , Bulgaria , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo Genético

RESUMEN

Gene amplification is a common mechanism for oncogene overexpression. High-level amplifications at 11q13 have been repeatedly found in bladder cancer by comparative genomic hybridization (CGH) and other techniques. Putative candidate oncogenes located in this region are CCND1 (PRAD1, bcl-1), EMS1, FGF3 (Int-2), and FGF4 (hst1, hstf1). To evaluate the involvement of these genes in bladder cancer, a tissue microarray (TMA) containing 2317 samples was screened by fluorescence in situ hybridization (FISH). The frequency of gains and amplifications of all genes increased significantly from stage pTa to pT1-4 and from low to high grade. In addition, amplification was associated with patient survival and progression of pT1 tumours. Among 123 tumours with amplifications, 68.3% showed amplification of all four genes; 19.5% amplification of CCND1, FGF4, and FGF3; and 0.8% co-amplification of FGF4, FGF3, and EMS1. Amplification of CCND1 alone was found in 9% of the tumours, while EMS1 alone was amplified in 1.6% and FGF4 in 0.8%. Overall, the amplification frequency decreased with increasing genomic distance from CCND1, suggesting that, among the genes examined, CCND1 is the major target gene in the 11q13 amplicon in bladder cancer.

Asunto(s)

Cromosomas Humanos Par 11/genética , Amplificación de Genes/genética , Genes bcl-1/genética , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Oncogenes/genética , Proteínas Proto-Oncogénicas/genética , Neoplasias de la Vejiga Urinaria/genética , Adenocarcinoma/genética , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Pequeñas/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Transicionales/genética , Cortactina , Ciclina D1/genética , ADN de Neoplasias/análisis , Femenino , Factor 3 de Crecimiento de Fibroblastos , Factor 4 de Crecimiento de Fibroblastos , Factores de Crecimiento de Fibroblastos/genética , Humanos , Hibridación Fluorescente in Situ/métodos , Masculino , Proteínas de Microfilamentos/genética , Persona de Mediana Edad , Estadificación de Neoplasias , Fenotipo , Pronóstico

RESUMEN

INTRODUCTION: Overexpression of the receptor Her-2 leads to increased proliferative response to epidermal growth factors which plays a key role in tumor development and growth. Increased oncoprotein level, in the majority of cases, is caused by erbB-2 gene amplification. To define the frequency of amplifications of erbB-2 in bladder cancer, and to determine their association with the tumor phenotype we utilized tissue microarray (TMA) approach. MATERIALS AND METHODS: We analyzed a TMA consisting of 159 transitional cell bladder carcinomas for erbB-2 gene amplification by dual-color FISH. RESULTS: The frequency of erbB-2 amplification was 5.3% of all successfully analyzed samples (4 of 75). It increased from minimally invasive (pT1) to muscle-invasive (pT2-4) tumors, as well as with advanced tumor grade (G1 to G2 to G3). All amplifications were cluster amplifications confirming the fact that erbB-2 amplification occurs intrachromosomally in bladder cancer. CONCLUSIONS: We concluded that despite its low incidence, erbB-2 amplification is of importance for the bladder tumor invasion and progression.

Asunto(s)

Genes erbB-2/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Neoplasias de la Vejiga Urinaria/genética , Adulto , Anciano , Anciano de 80 o más Años , Bulgaria , Femenino , Humanos , Masculino , Persona de Mediana Edad