RESUMEN
Cancer and neurodegenerative disorders present overwhelming challenges for healthcare worldwide. Epidemiological studies showed a decrease in cancer rates in patients with neurodegenerative disorders, including the Huntington disease (HD). Apoptosis is one of the most important processes for both cancer and neurodegeneration. We suggest that genes closely connected with apoptosis and associated with HD may affect carcinogenesis. We applied reconstruction and analysis of gene networks associated with HD and apoptosis and identified potentially important genes for inverse comorbidity of cancer and HD. The top 10 high-priority candidate genes included APOE, PSEN1, INS, IL6, SQSTM1, SP1, HTT, LEP, HSPA4, and BDNF. Functional analysis of these genes was carried out using gene ontology and KEGG pathways. By exploring genome-wide association study results, we identified genes associated with neurodegenerative and oncological disorders, as well as their endophenotypes and risk factors. We used publicly available datasets of HD and breast and prostate cancers to analyze the expression of the identified genes. Functional modules of these genes were characterized according to disease-specific tissues. This integrative approach revealed that these genes predominantly exert similar functions in different tissues. Apoptosis along with lipid metabolism dysregulation and cell homeostasis maintenance in the response to environmental stimulus and drugs are likely key processes in inverse comorbidity of cancer in patients with HD. Overall, the identified genes represent the promising targets for studying molecular relations of cancer and HD.
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Enfermedad de Huntington , Neoplasias , Enfermedades Neurodegenerativas , Masculino , Humanos , Enfermedad de Huntington/epidemiología , Enfermedad de Huntington/genética , Enfermedad de Huntington/metabolismo , Estudio de Asociación del Genoma Completo , Redes Reguladoras de Genes , Neoplasias/epidemiología , Neoplasias/genéticaRESUMEN
BACKGROUND: Recent studies have focused on the potential role of epicardial adipose tissue (EAT) in the development of coronary artery disease (CAD). ABCA1 and ABCG1 transporters regulate cell cholesterol content and reverse cholesterol transport. We aimed to determine whether DNA methylation and mRNA levels of the ABCA1 and ABCG1 genes in EAT and subcutaneous adipose tissue (SAT) were associated with CAD. METHODS: Paired EAT and SAT samples were collected from 82 patients undergoing elective cardiac surgery either for coronary artery bypass grafting (CAD group, N = 66) or valve surgery (NCAD group, N = 16). ABCA1 and ABCG1 mRNA levels in EAT and SAT samples were analyzed using real time polymerase chain reaction, ABCA1 protein levels in EAT samples were assessed by western blotting. ABCA1 and ABCG1 DNA methylation analysis was performed in 24 samples from the CAD group and 9 samples from the NCAD group via pyrosequencing. RESULTS: DNA methylation levels in the ABCA1 promoter and ABCG1 cg27243685 and cg06500161 CpG sites were higher in EAT samples from patients with CAD compared with NCAD (21.92% vs 10.81%, p = 0.003; 71.51% vs 68.42%, p = 0.024; 46.11% vs 37.79%, p = 0.016, respectively). In patients with CAD, ABCA1 and ABCG1 DNA methylation levels were higher in EAT than in SAT samples (p < 0.05). ABCA1 mRNA levels in EAT samples were reduced in the subgroup of patients with CAD and concomitant carotid artery disease or peripheral artery disease compared with the NCAD group (p = 0.024). ABCA1 protein levels in EAT samples tended to be lower in CAD patients than in the NCAD group (p = 0.053). DNA methylation levels at the ABCG1 cg27243685 site positively correlated with plasma triglyceride concentration (r = 0.510, p = 0.008), body mass index (r = 0.556, p = 0.013) and waist-to-hip ratio (r = 0.504, p = 0.012) in SAT samples. CONCLUSION: CAD is associated with ABCA1 and ABCG1 DNA hypermethylation in EAT. CAD with concomitant carotid artery disease or peripheral artery disease is accompanied by decreased ABCA1 gene expression in EAT. DNA methylation levels at the ABCG1 cg27243685 locus in SAT are associated with hypertriglyceridemia and obesity.
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Transportador 1 de Casete de Unión a ATP/genética , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1/genética , Tejido Adiposo/metabolismo , Enfermedad de la Arteria Coronaria/genética , Metilación de ADN , Pericardio/metabolismo , Transportador 1 de Casete de Unión a ATP/metabolismo , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 1/metabolismo , Adulto , Anciano , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/metabolismo , Islas de CpG , Femenino , Regulación de la Expresión Génica , Humanos , Hipertrigliceridemia/genética , Hipertrigliceridemia/metabolismo , Masculino , Persona de Mediana Edad , Obesidad/genética , Obesidad/metabolismo , Enfermedad Arterial Periférica/genética , Enfermedad Arterial Periférica/metabolismo , Regiones Promotoras GenéticasRESUMEN
Co-existence of bronchial asthma (BA) and tuberculosis (TB) is extremely uncommon (dystropic). We assume that this is caused by the interplay between genes involved into specific pathophysiological pathways that arrest simultaneous manifestation of BA and TB. Identification of common and specific genes may be important to determine the molecular genetic mechanisms leading to rare co-occurrence of these diseases and may contribute to the identification of susceptibility genes for each of these dystropic diseases. To address the issue, we propose a new methodological strategy that is based on reconstruction of associative networks that represent molecular relationships between proteins/genes associated with BA and TB, thus facilitating a better understanding of the biological context of antagonistic relationships between the diseases. The results of our study revealed a number of proteins/genes important for the development of both BA and TB.
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Asma/genética , Asma/fisiopatología , Redes Reguladoras de Genes , Tuberculosis/genética , Tuberculosis/fisiopatología , Algoritmos , Asma/inmunología , Predisposición Genética a la Enfermedad , Humanos , Fenómenos Inmunogenéticos , Modelos Genéticos , Proteínas/genética , Proteínas/inmunología , Tuberculosis/inmunologíaRESUMEN
BACKGROUND: Hypertrophic cardiomyopathy is the most frequent autosomal dominant disease, yet due to genetic heterogeneity, incomplete penetrance, and phenotype variability, the prognosis of the disease course in pathogenic variant carriers remains an issue. Identifying common patterns among the effects of different genetic variants is important. METHODS: We investigated the cause of familial hypertrophic cardiomyopathy (HCM) in a family with two patients suffering from a particularly severe disease. Searching for the genetic variants in HCM genes was performed using different sequencing methods. RESULTS: A new missense variant, p.Leu714Arg, was identified in exon 19 of the beta-myosin heavy chain gene (MYH7). The mutation was found in a region that encodes the 'converter domain' in the globular myosin head. This domain is essential for the conformational change of myosin during ATP cleavage and contraction cycle. Most reports on different mutations in this region describe severe phenotypic consequences. The two patients with the p.Leu714Arg mutation had heart failure early in life and died from HCM complications. CONCLUSIONS: This case presents a new likely pathogenic variant in MYH7 and supports the hypothesis that myosin converter mutations constitute a subclass of HCM mutations with a poor prognosis for the patient.
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Cardiomiopatía Hipertrófica Familiar , Cardiomiopatía Hipertrófica , Humanos , Miosinas Cardíacas/genética , Cardiomiopatía Hipertrófica/genética , Cardiomiopatía Hipertrófica Familiar/diagnóstico por imagen , Cardiomiopatía Hipertrófica Familiar/genética , Mutación , Mutación Missense/genética , Cadenas Pesadas de Miosina/genética , FenotipoRESUMEN
Leprosy is an infectious disease caused by the obligate intracellular pathogen Mycobacterium leprae and remains endemic in many parts of the world. Despite several major studies on susceptibility to leprosy, few genomic loci have been replicated independently. We have conducted an association analysis of more than 1,500 individuals from different case-control and family studies, and observed consistent associations between genetic variants in both TLR1 and the HLA-DRB1/DQA1 regions with susceptibility to leprosy (TLR1 I602S, case-control P = 5.7 x 10(-8), OR = 0.31, 95% CI = 0.20-0.48, and HLA-DQA1 rs1071630, case-control P = 4.9 x 10(-14), OR = 0.43, 95% CI = 0.35-0.54). The effect sizes of these associations suggest that TLR1 and HLA-DRB1/DQA1 are major susceptibility genes in susceptibility to leprosy. Further population differentiation analysis shows that the TLR1 locus is extremely differentiated. The protective dysfunctional 602S allele is rare in Africa but expands to become the dominant allele among individuals of European descent. This supports the hypothesis that this locus may be under selection from mycobacteria or other pathogens that are recognized by TLR1 and its co-receptors. These observations provide insight into the long standing host-pathogen relationship between human and mycobacteria and highlight the key role of the TLR pathway in infectious diseases.
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Predisposición Genética a la Enfermedad/genética , Antígenos HLA-DR/genética , Lepra/genética , Receptor Toll-Like 1/genética , Frecuencia de los Genes , Estudio de Asociación del Genoma Completo , Antígenos HLA-DQ/genética , Cadenas alfa de HLA-DQ , Cadenas HLA-DRB1 , Humanos , Lepra/inmunología , Mycobacterium leprae/inmunología , Receptor Toll-Like 1/inmunologíaRESUMEN
The objective of this study was to identify genes targeted by both copy number and copy-neutral changes in the right coronary arteries in the area of advanced atherosclerotic plaques and intact internal mammary arteries derived from the same individuals with comorbid coronary artery disease and metabolic syndrome. The artery samples from 10 patients were screened for genomic imbalances using array comparative genomic hybridization. Ninety high-confidence, identical copy number variations (CNVs) were detected. We also identified eight copy-neutral changes (cn-LOHs) > 1.5 Mb in paired arterial samples in 4 of 10 individuals. The frequencies of the two gains located in the 10q24.31 (ERLIN1) and 12q24.11 (UNG, ACACB) genomic regions were evaluated in 33 paired arteries and blood samples. Two patients contained the gain in 10q24.31 (ERLIN1) and one patient contained the gain in 12q24.11 (UNG, ACACB) that affected only the blood DNA. An additional two patients harboured these CNVs in both the arteries and blood. In conclusion, we discovered and confirmed a gain of the 10q24.31 (ERLIN1) and 12q24.11 (UNG, ACACB) genomic regions in patients with coronary artery disease and metabolic comorbidity. Analysis of DNA extracted from blood indicated a possible somatic origin for these CNVs.
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Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/genética , Genómica , Síndrome Metabólico/epidemiología , Síndrome Metabólico/genética , Comorbilidad , Hibridación Genómica Comparativa , Enfermedad de la Arteria Coronaria/genética , Variaciones en el Número de Copia de ADN/genética , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
OBJECTIVES: Atypical familial mycobacteriosis (AFM, OMIM #209950) is caused by mutations in genes regulating IL12/IFNG pathway. Some of the mutations exhibit incomplete penetrance, and they have been proposed to be involved in the common (polygenic) predisposition to tuberculosis (TB). We set out to test this hypothesis in two populations from Siberian region of Russia with high prevalence of TB. MATERIAL AND METHODS: The prevalence of twelve mutations in IL12/IFNG pathway genes of were analysed in 331 Russians and 238 Tuvinians TB patients and in 279 healthy Russians and 265 healthy Tuvinians. A screening for new mutations and rare polymorphisms was carried out in 10 children with severe generalized TB and severe BCG-vaccine complications using Sanger's bidirectional sequencing. RESULTS: Twelve mutations most commonly identified in AFM patients appeared to be "wild-type" monomorphic in the studied groups. No new mutations or rare polymorphisms were identified by sequencing. However, 15 common single nucleotide polymorphisms were found, none of which was associated with TB after correction for multiple testing. CONCLUSION: The results of the study contradict with a hypothesis that mutations underlying AFM syndrome are involved in the predisposition to TB.
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Mutación , Infecciones por Mycobacterium no Tuberculosas/genética , Tuberculosis/genética , Adolescente , Adulto , Estudios de Casos y Controles , Niño , Femenino , Predisposición Genética a la Enfermedad , Humanos , Subunidad p40 de la Interleucina-12/genética , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Receptores de Interferón/genética , Receptores de Interleucina-12/genética , Factor de Transcripción STAT1/genética , Adulto Joven , Receptor de Interferón gammaRESUMEN
Epigenetic mechanisms of gene regulation in context of cardiovascular diseases are of considerable interest. So far, our current knowledge of the DNA methylation profiles for atherosclerosis affected and healthy human vascular tissues is still limited. Using the Illumina Infinium Human Methylation27 BeadChip, we performed a genome-wide analysis of DNA methylation in right coronary artery in the area of advanced atherosclerotic plaques, atherosclerotic-resistant internal mammary arteries, and great saphenous veins obtained from same patients with coronary heart disease. The resulting DNA methylation patterns were markedly different between all the vascular tissues. The genes hypomethylated in athero-prone arteries to compare with atherosclerotic-resistant arteries were predominately involved in regulation of inflammation and immune processes, as well as development. The great saphenous veins exhibited an increase of the DNA methylation age in comparison to the internal mammary arteries. Gene ontology analysis for genes harboring hypermethylated CpG-sites in veins revealed the enrichment for biological processes associated with the development. Four CpG-sites located within the MIR10B gene sequence and about 1 kb upstream of the HOXD4 gene were also confirmed as hypomethylated in the independent dataset of the right coronary arteries in the area of advanced atherosclerotic plaques in comparison with the other vascular tissues. The DNA methylation differences observed in vascular tissues of patients with coronary heart disease can provide new insights into the mechanisms underlying the development of pathology and explanation for the difference in graft patency after coronary artery bypass grafting surgery.
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Aterosclerosis/genética , Enfermedad Coronaria/genética , Vasos Coronarios/metabolismo , Epigénesis Genética , Arterias Mamarias/metabolismo , Placa Aterosclerótica/genética , Vena Safena/metabolismo , Anciano , Aterosclerosis/metabolismo , Aterosclerosis/patología , Enfermedad Coronaria/metabolismo , Enfermedad Coronaria/patología , Vasos Coronarios/patología , Islas de CpG , Metilación de ADN , Femenino , Estudio de Asociación del Genoma Completo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Masculino , Arterias Mamarias/patología , MicroARNs/genética , MicroARNs/metabolismo , Persona de Mediana Edad , Anotación de Secuencia Molecular , Especificidad de Órganos , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patología , Vena Safena/patologíaRESUMEN
Eczema often precedes the development of asthma in a disease course called the 'atopic march'. To unravel the genes underlying this characteristic pattern of allergic disease, we conduct a multi-stage genome-wide association study on infantile eczema followed by childhood asthma in 12 populations including 2,428 cases and 17,034 controls. Here we report two novel loci specific for the combined eczema plus asthma phenotype, which are associated with allergic disease for the first time; rs9357733 located in EFHC1 on chromosome 6p12.3 (OR 1.27; P=2.1 × 10(-8)) and rs993226 between TMTC2 and SLC6A15 on chromosome 12q21.3 (OR 1.58; P=5.3 × 10(-9)). Additional susceptibility loci identified at genome-wide significance are FLG (1q21.3), IL4/KIF3A (5q31.1), AP5B1/OVOL1 (11q13.1), C11orf30/LRRC32 (11q13.5) and IKZF3 (17q21). We show that predominantly eczema loci increase the risk for the atopic march. Our findings suggest that eczema may play an important role in the development of asthma after eczema.
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Asma/genética , Dermatitis Atópica/genética , Proteínas Adaptadoras del Transporte Vesicular/genética , Adolescente , Adulto , Sistemas de Transporte de Aminoácidos Neutros/genética , Proteínas de Unión al Calcio/genética , Proteínas Portadoras/genética , Niño , Preescolar , Proteínas de Unión al ADN/genética , Progresión de la Enfermedad , Femenino , Proteínas Filagrina , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Factor de Transcripción Ikaros/genética , Interleucina-4/genética , Cinesinas/genética , Modelos Logísticos , Masculino , Proteínas de la Membrana/genética , Persona de Mediana Edad , Proteínas de Neoplasias/genética , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Fenotipo , Polimorfismo de Nucleótido Simple , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/genética , Proteínas Represoras/genética , Factores de Transcripción/genética , Adulto JovenRESUMEN
According to epidemiological observations, Opisthorchis felineus liver fluke invasion is negatively associated with the development and severity of allergic diseases in endemic regions of Russia. We hypothesized that the invasion is an important factor in gene-environmental interactions (GEI) underlying allergy. To prove this, we tested 10 single nucleotide polymorphisms of immune response modifying genes in 428 individuals stratified by atopic bronchial asthma presence and O. felineus invasion. Using regression models, a statistically significant interaction between the rs6737848 polymorphism of SOCS5 gene and O. felineus invasion was observed (pint=0.001, OR=5.66, 95% CI 1.96-16.31 for dominant model; pint=0.003; OR=4.38, 95% CI 1.68-11.45 for additive model). The interaction is based on the statistically significant association between the SOCS5 gene and atopic bronchial asthma in patients without O. felineus infection, while no such association is seen in patients infected by the helminth. These data confirm for the first time the importance of the helminth invasion as an environmental factor influencing the association between genetic factors and atopic bronchial asthma. In particular, O. felineus diminishes the risk of atopic bronchial asthma associated with the SOCS5 gene polymorphism.
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Asma/genética , Interacción Gen-Ambiente , Opistorquiasis/complicaciones , Proteínas Supresoras de la Señalización de Citocinas/genética , Adulto , Animales , Asma/parasitología , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Opisthorchis , Polimorfismo de Nucleótido Simple , Factores de Riesgo , Federación de Rusia , Adulto JovenRESUMEN
The concept of syntropic diseases was proposed at the beginning of the last century to emphasize the phenomenon of nonrandom co-occurrence of human disorders. Common genes underlying specific syntropic diseases were called syntropic genes. The application of this concept to contemporary genomic studies will facilitate the understanding of the molecular basis of complex diseases, provide future direction for discovering new targets for therapy and prognosis, and may even lead to the reassessment of disease classification for the practice of more precise personalized medicine. With the acceptance of the syntropic genes theory, new genetic tests, focused on markers pointing to a set of pathogenetically linked diseases rather than to a single nosology, can be developed.
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Many new genetic tests for common multifactorial disorders are becoming available to individuals, including direct-to-consumer genotyping services. Typically, studies of public attitudes reveal a high level of interest for individual genotyping. In a Russian urban population, 85% of 2000 respondents answered positively to a question about their own willingness to undergo predictive genetic testing for preventable health conditions. Gender, age and health status significantly influenced response. Multivariate discriminant analyses revealed that wanting to know about probable future diseases, readiness to improve lifestyles and an interest in learning about individual genome characteristics are the most important predictors for wanting to be tested. Along with the high level of interest, highly overestimated expectations were encountered in many studies. With the low predictive abilities of currently available genetic tests for common disorders, proper interpretation of the data and genetic counseling are essential. There is a need for prospective validation of genetic panels for risk assessments, and for efforts to measure the effects of genetic information disclosure and how this information might contribute to lifestyle changes.
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We propose a novel universal methodology, Short Oligonucleotide Tandem Ligation Assay (SOTLA), for SNP genotyping. SOTLA is based on using a tandem of short oligonucleotide (TSO) probes consisting of three fragments: the core oligonucleotide and two flanking oligomers, one of which is immobilized onto a solid support and another one contains the biotin label. TSO is self-associated on a complementary DNA template, forms the complex containing two nicks, which are efficiently ligated with DNA ligase giving biotinylated oligonucleotide covalently bound to polymer beads. No ligation of TSO on an imperfect DNA template bearing the base substitution in the core binding site is occurred. We used SOTLA for the highly selective SNP analysis in different DNA fragments of human Y chromosome. Comparison of SOTLA results with those of PCR-RFLP and allele-specific PCR techniques demonstrates that SOTLA ensures the univocal reliable SNP analysis in different PCR fragments varying in length and base composition. The fundamental difference between SOTLA and well known OLA approaches while using T4 DNA ligase is that the accuracy of SNP analysis in OLA is ensured only by the specificity of ligase while that in SOTLA is provided by the specificity of both ligation and hybridization of TSO probes.
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Bioensayo/métodos , Cromosomas Humanos Y/genética , Análisis Mutacional de ADN/métodos , Polimorfismo de Nucleótido Simple/genética , Análisis de Secuencia de ADN/métodos , Secuencias Repetidas en Tándem/genética , Secuencia de Bases , Genotipo , Humanos , Datos de Secuencia Molecular , Mutación PuntualRESUMEN
Allele frequencies for 15 STRs (CSF1PO, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, FGA, Penta D, Penta E, THO1, TPOX, and vWA) in the PowerPlex 16 System (Promega Corporation) were assessed in 386 individuals from five Russian urban populations. No significant between-population differences in frequencies and molecular variance of 15 microsatellites were revealed. For all 15 loci, the combined matching probability is 3.19 x 10(-18) and the power of exclusion is 99.99989%.
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Variación Genética , Genética de Población , Secuencias Repetidas en Tándem/genética , Población Blanca/genética , Alelos , Genética Forense , Frecuencia de los Genes , Humanos , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Federación de RusiaRESUMEN
In contrast to the modest progress made in the interpretation and clinical application of genomic data, genotyping technologies have experienced great progress. Genotyping costs are progressively decreasing making individual genotyping more commonly available. Financial availability of individual genome analysis and the strong desire of many people to know about their individual genomic characteristics, promotes the marketing of genetic tests of variable predictive value directly to the public. A survey of 2000 Russian respondents revealed very positive attitudes and beliefs towards these genetic developments: 85% of surveyed individuals would like to have their genetic risk for avoidable diseases estimated, and 89% responded stating that they would try to change their lifestyle by giving up bad habits, following a recommended diet or taking medications if a high risk of disease was identified. It is believed that with time, validated genetic information will find its rightful place in medicine, by supplementing phenotypic clinical data with validated genetic interpretations.
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In Russian population of Siberia asthma is usually concomitant with high sensitization to indoor allergens (cat, dog and house dust mites), overproduction of total immunoglobulin E (IgE) and airway hyperreactivity. Definition of genes that predispose to development of various sub-components of the asthma phenotype is important for understanding of etiology of this disease. To map genes predisposing to asthma, we tested 21 microsatellite markers from candidate chromosomal regions in 136 Russian nuclear families with asthma from Siberia. We performed non-parametric analysis for linkage with asthma, total IgE, specific IgE to cat, dog, and dust mites, and spirometric indices (FEV1 (%) - percentage of predicted forced expiratory volume in 1s, FVC (%) - percentage of predicted forced vital capacity, and FEV1/FVC (%) - Tiffenau index). The most significant linkage was to the candidate region on chromosome 12. Locus controlling cat-specific IgE, which is the most abundant in asthma patients from Siberian population, mapped within the interval between 136 and 140 cM on chromosome 12q24.3, with the suggestive linkage at the marker D12S1611 (LOD=2.23, P=0.0007). Total IgE was also linked to this region (D12S1611 - LOD=1.12, P=0.012). FEV1 (%) exceeded LOD>1 threshold for significance with the same locus 12q24.3, but with the peak at a more proximal region at 111.87 cM (D12S338 - LOD=1.21, P=0.009). Some evidence of linkage (LOD>1.0) was also detected for asthma at 6p21.31 (D6S291) and total IgE at 13q14.2 (D13S165). These data indicate that the locus 12q24.3 is the most promising candidate for identification of asthma genes in Russian population of Siberia.
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Asma/epidemiología , Asma/genética , Gatos/inmunología , Cromosomas Humanos Par 12/genética , Repeticiones de Microsatélite/genética , Adolescente , Adulto , Alérgenos/inmunología , Animales , Asma/inmunología , Niño , Mapeo Cromosómico , Perros , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Inmunoglobulina E/sangre , Masculino , Repeticiones de Microsatélite/inmunología , Persona de Mediana Edad , Linaje , Pyroglyphidae/inmunología , Siberia/epidemiologíaRESUMEN
Two polymorphisms in the IL4 (G/C 3'-UTR) and IL5 (C-703T) genes were studied in a sample of families whose probands had atopic bronchial asthma (BA) (66 families, n = 183) and in a group of non-cognate individuals with the severe form of the disease (n = 34). The samples were collected from the Russian population in the city of Tomsk (Russia). Using the transmission/disequilibrium test (TDT), a significant association of allele C-703 IL5 with BA was established (TDT = 4.923, p = 0.007 +/- 0.0007). The analysis of 40 individuals with mild asthma and 49 patients with the severe form of the disease revealed a negative association of genotype GG IL4 (OR = 0.39, 95% CI = 0.15-0.99, p = 0.035), and also a trend towards a positive association of the GC IL4 genotype (OR = 2.52, 95% CI = 0.98-6.57, p = 0.052) with mild BA. There was a concordance of the clinical classification of BA severity with the 'genotype' (McNemar's chi(2) test with continuity correction constituted 0.03, d.f. = 1, p = 0.859). These results suggest that polymorphisms in the IL4 and IL5 genes contribute to the susceptibility to atopic BA and could determine the clinical course of the disease.
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Alu elements, the largest family of interspersed repeats, mobilize throughout the genomes of primates by retroposition. Alu are present in humans in an excess of 500 000 copies per haploid genome. Since some of the insertion alleles have not reached fixation, they remain polymorphic and can be used as biallelic DNA marker systems in investigations of human evolution. In this study, six polymorphic Alu insertional (PAI) loci were used as genetic markers. These markers are thought to be selectively neutral. The presence of these six PAIs was determined by a polymerase chain reaction (PCR)-based assay in 1646 individuals from 47 populations from around the world. Examination of the populations by plotting the first and second principal components, shows the expected segregation of populations according to geographical vicinity and established ethnic affinities. Centroid analysis demonstrated that sub-Sahara populations have experienced higher than average gene flow and/or represent larger populations as compared to groups in other parts of the globe and especially to known inbreed populations. This is consistent with greater heterogeneity and diversity expected of source groups. In addition, maximum likelihood (ML) analyses were performed with these 47 populations and a hypothetical ancestral group lacking the insertion in all six loci. Analysis of our data supports the Out of Africa hypothesis. African populations and admixed groups of African descent formed a single monophyletic group with a basal placement on the tree, which grouped closest to the hypothetical ancestor.