RESUMO
We investigated whether the polymorphisms rs133946 and rs133945 in the promoter region of the synapsin III (SYN3) gene are associated with multiple sclerosis in German patients. Association of the SYN3 variations and haplotypes with MS is not evident in German MS patients - in contrast to a MS cohort from Italy, as reported previously.
Assuntos
Esclerose Múltipla/epidemiologia , Esclerose Múltipla/genética , Polimorfismo Genético/genética , Sinapsinas/genética , Alelos , Frequência do Gene , Genótipo , Alemanha/epidemiologia , HumanosRESUMO
Electrophoretic separation of nucleic acids according to their molecular weights has dominated the methods' spectrum in molecular genetics for nearly half a century. We review the current methodological basis and evaluate its impact with special reference to new developments in the microarray technology. Although electrophoresis may be made redundant for many applications in DNA diagnostics within a few years, a number of electrophoretic vestiges will remain irreplaceable in the foreseeable future.
Assuntos
DNA/genética , DNA/isolamento & purificação , Eletroforese/métodos , Northern Blotting , Southern Blotting , Cromatografia Líquida de Alta Pressão , Eletroforese/tendências , Eletroforese em Gel de Ágar , Eletroforese Capilar , Humanos , Técnicas Analíticas Microfluídicas , Repetições de Microssatélites , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Fragmento de Restrição , Polimorfismo Conformacional de Fita Simples , Análise de Sequência de DNARESUMO
Apoptosis, the programmed death of cells, plays a distinct role in the etiopathogenesis of Multiple sclerosis (MS), a common disease of the central nervous system with complex genetic background. Yet, it is not clear whether the impact of apoptosis is due to altered apoptotic behaviour caused by variations of apoptosis-related genes. Instead, apoptosis in MS may also represent a secondary response to cellular stress during acute inflammation in the central nervous system. Here, we screened 202 apoptosis-related genes for association by genotyping 202 microsatellite markers in initially 160 MS patients and 160 controls, both divided in 4 sets of pooled DNA samples, respectively. When applying Bonferroni correction, no significant differences in allele frequencies were detected between MS patients and controls. Nevertheless, we chose 7 markers for retyping in individual DNA samples, thereby eliminating 6 markers from the list of candidates. The remaining candidate, the ERBB3 gene microsatellite, was genotyped in additional 245 MS patients and controls. No association of the ERBB3 marker with the disease was detected in these additional cohorts. In consequence, we did not find further evidence for apoptosis-related genes as predisposition factors in MS.
Assuntos
Apoptose/genética , Marcadores Genéticos , Predisposição Genética para Doença , Repetições de Microssatélites/genética , Esclerose Múltipla/genética , Sequência de Bases , Estudos de Casos e Controles , Primers do DNA , Eletroforese em Gel de Poliacrilamida , Frequência do Gene , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Reação em Cadeia da PolimeraseRESUMO
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system, with a complex genetic background. Here, we present a genome screen for association in small scale, employing 11,555 single nucleotide polymorphisms (SNPs) on DNA chips for genotyping 100 MS patients stratified for HLA-DR2+ and 100 controls. More than 500 SNPs revealed significant differences between cases and controls before Bonferroni correction. A fraction of these SNPs was reanalysed in two additional cohorts of patients and controls, using high-throughput genotyping methods. A marker on chromosome 6p21.32 (rs2395182) yielded the highest significance level, validating the established HLA-DR association.
Assuntos
Antígenos HLA-DR/genética , Antígeno HLA-DR2/genética , Esclerose Múltipla/genética , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único , Ligação Genética , Marcadores Genéticos , Testes Genéticos , Genoma , Cadeias HLA-DRB1 , Humanos , Esclerose Múltipla/etiologiaRESUMO
Multiple sclerosis (MS) is a demyelinating disease of the central nervous system with a complex genetic background. In order to identify loci associated with the disease, we had performed a genome screen initially using 6000 microsatellite markers in pooled DNA samples of 198 MS patients and 198 controls. Here, we report on the detailed reanalysis of this set of data. Distinctive features of microsatellites genotyped in pooled DNA causing false-positive association or masking existing association were met by improved evaluation and refined correction factors in the statistical analyses. In order to assess potential errors introduced by DNA pooling and genotyping, we resurveyed the experiment in a subset of microsatellite markers using de novo-composed DNA pools. True MS associations of markers were verified via genotyping all individual DNA samples comprised in the pools. Microsatellites share characteristically superb information content but they do not lend themselves to automation in very large scale formats. Especially after DNA pooling many artifacts of individual marker systems require special attention and treatment. Therefore, in the near future comprehensive whole-genome screens may rather be performed by typing single nucleotide polymorphisms on chip-based platforms.
