Search results for "genotyping"
showing 10 items of 250 documents
Closing the case ofAPOEin multiple sclerosis: no association with disease risk in over 29 000 subjects: Figure 1
2012
Background Single nucleotide polymorphisms (SNPs) rs429358 (e4) and rs7412 (e2), both invoking changes in the amino-acid sequence of the apolipoprotein E (APOE) gene, have previously been tested for association with multiple sclerosis (MS) risk. However, none of these studies was sufficiently powered to detect modest effect sizes at acceptable type-I error rates. As both SNPs are only imperfectly captured on commonly used microarray genotyping platforms, their evaluation in the context of genome-wide association studies has been hindered until recently. Methods We genotyped 12 740 subjects hitherto not studied for their APOE status, imputed raw genotype data from 8739 subjects from five ind…
Analysis of extended genomic rearrangements in oncological research.
2007
Screening for genomic rearrangements is a fundamental task in the genetic diagnosis of many inherited disorders including cancer-predisposing syndromes. Several methods were developed for analysis of structural genomic abnormalities, some are targeted to the analysis of one or few specific loci, others are designed to scan the whole genome. Locus-specific methods are used when the candidate loci responsible for the specific pathological condition are known. Whole-genome methods are used to discover loci bearing structural abnormalities when the disease-associated locus is unknown. Three main approaches have been employed for the analysis of locus-specific structural changes. The first two a…
Real-time PCR detection of Pseudomonas aeruginosa in clinical and municipal wastewater and genotyping of the ciprofloxacin-resistant isolates
2006
Real-time quantification of Pseudomonas aeruginosa was performed in various wastewater systems including clinical, municipal wastewaters and inflow from a wastewater treatment plant. The highest concentrations of P. aeruginosa-specific targets were detected in clinical wastewaters. Limitations of the detection system resulting from inhibition or cross-reaction were identified. Ciprofloxacin-resistant P. aeruginosa strains were isolated after specific enrichment from clinical and municipal wastewaters. In some cases they were also cultivated from effluent of a wastewater treatment plant, and from its downstream river water. A total of 119 isolates were phenotypically characterized as ciprofl…
Analysis of the Single-Nucleotide Polymorphism in the 5′UTR and Part of Intron I of the Sheep MSTN Gene
2011
The myostatin (MSTN) gene region encompassing the 5′UTR and part of intron I was sequenced in animals of two herds of Latvian Darkhead sheep to extend data on the ovine MSTN gene polymorphism and to provide information useful for local breed conservation. Two and four polymorphic loci were revealed in the 5′UTR and intron I. Four and five local haplotypes were constructed, respectively. The genotyping data obtained and that previously reported for the same genomic region were combined in one dataset for the haplotype analysis. Recombination events were detected between loci (c.−40, c.−37) in the 5′UTR and (c.373+18, c.373+101) and (c.373+101, c.373+241) in intron I. Single-nucleotide polymo…
Forensic typing of autosomal SNPs with a 29 SNP-multiplex--results of a collaborative EDNAP exercise.
2008
We report the results of an inter-laboratory exercise on typing of autosomal single nucleotide polymorphisms (SNP) for forensic genetic investigations in crime cases. The European DNA Profiling Group (EDNAP), a working group under the International Society for Forensic Genetics (ISFG), organised the exercise. A total of 11 European and one US forensic genetic laboratories tested a subset of a 52 SNP-multiplex PCR kit developed by the SNPforID consortium. The 52 SNP-multiplex kit amplifies 52 DNA fragments with 52 autosomal SNP loci in one multiplex PCR. The 52 SNPs are detected in two separate single base extension (SBE) multiplex reactions with 29 and 23 SNPs, respectively, using SNaPshot …
Laser Pressure Catapulting (LPC): Optimization LPC-System and Genotyping of Colorectal Carcinomas
2005
Genotype analysis is becoming more and more useful in clinical practice, since specific mutations in tumors often correlate with prognosis and/or therapeutic response. Unfortunately, current molecular analytical techniques often require time-consuming and costly steps of analysis, thus making their routine clinical use difficult. Moreover, one of the most difficult problems arising during tumor research is that of their cell heterogeneity, which depends on their clear molecular heterogeneity. SSCP analysis discriminates by means of aberrant electrophoresis migration bands, mutated alleles which may represent as little as 15-20% of their total number. Nevertheless, in order to identify by se…
GENETIC POLYMORPHISM OF THE FOURTH COMPONENT OF HUMAN COMPLEMENT: POPULATION STUDY AND PROPOSAL FOR A REVISED NOMENCLATURE BASED ON GENOMIC PCR TYPIN…
1996
SUMMARY The fourth component of human complement (C4) is coded for by two homologous genes, C4A and C4B, located in the class III region of the major histocompatibility complex (MHC). Genetic typing of C4A and B alleles is routinely carried out by high-voltage agarose gel electrophoresis. The electrophoretic C4 polymorphism can be further subdivided by the Rodgers (Rg) and Chido (Ch) blood groups, which are antigenic determinants of the C4A and B alpha-chains, respectively. We have used a recently described direct PCR typing method using sequence-specific primers (PCR-SSP) in combination with electrophoretic C4 typing as well as genomic RFLP analysis to determine the frequency of C4 allotyp…
A multiplex SNP typing approach for the DNA pyrosequencing technology
2006
Abstract We have developed a multiplex Pyrosequencing assay which enables the simultaneous analyses of 23 single nucleotide polymorphisms (SNPs) from the human genome selected by the SNPforID Consortium. In our investigations we have studied the multiplex capacity of the PSQ™ 96MA instrument (Biotage AB). To test the reliability of SNP typing by Pyrosequencing the SNPs were analysed in parallel by using the SNaPshot minisequencing technique as reference method.
Mixture analysis using SWaP™ SNPs and non-biallelic SNPs
2006
Abstract Improved analysis of degraded samples, increased throughput, and a wider choice of typing platforms are some of the significant advantages offered by single nucleotide polymorphism (SNP) genotyping over established short tandem repeat (STR)-based systems. However, DNA mixtures present a considerable problem to SNP analysis as there is currently no generally accepted technique that allows recognition of the presence of a mixed profile or identification of the individual contributors. We present the first demonstration of SNP mixture analysis with an approach based upon the use of two rare subsets of SNPs: SWaP™ SNPs and non-biallelic SNPs and discuss their value for forensic mixture…
Identification and prevention of genotyping errors caused by G-quadruplex- and i-motif-like sequences.
2009
Abstract Background: Reliable PCR amplification of DNA fragments is the prerequisite for most genetic assays. We investigated the impact of G-quadruplex– or i-motif–like sequences on the reliability of PCR-based genetic analyses. Methods: We found the sequence context of a common intronic polymorphism in the MEN1 gene (multiple endocrine neoplasia I) to be the cause of systematic genotyping errors by inducing preferential amplification of one allelic variant [allele dropout (ADO)]. Bioinformatic analyses and pyrosequencing-based allele quantification enabled the identification of the underlying DNA structures. Results: We showed that G-quadruplex– or i-motif–like sequences can reproducibly …