Search results for " Polymorphism."
showing 10 items of 1006 documents
Cis-epistasis at the LPA locus and risk of cardiovascular diseases.
2022
AIMS Coronary artery disease (CAD) has a strong genetic predisposition. However, despite substantial discoveries made by genome-wide association studies (GWAS), a large proportion of heritability awaits identification. Non-additive genetic-effects might be responsible for part of the unaccounted genetic variance. Here we attempted a proof-of-concept study to identify non-additive genetic effects, namely epistatic interactions, associated with CAD. METHODS AND RESULTS We tested for epistatic interactions in ten CAD case-control studies and UK Biobank with focus on 8,068 SNPs at 56 loci with known associations with CAD risk. We identified a SNP pair located in cis at the LPA locus, rs1800769 …
Changes in chromosomal polymorphism when selecting for a neutral trait inDrosophila subobscura
1986
The changes which occurred in the chromosomal polymorphism ofDrosophila subobscura when selecting for abdominal bristle number were analysed. A decrease in the diversity of arrangements and an increase in homozygosity over the selection experiment were found. These changes were stronger in selection than in control lines.
Characterization of polymorphisms in the toxin A and B genes of Clostridium difficile.
2006
We have used six independent polymerase chain reactions (A1–A3 and B1–B3) for amplification of the entire sequence of the two toxin genes tcdA and tcdB of several Clostridium difficile strains. With this approach we have detected (1) restriction site polymorphisms which are distributed all over the genes, and (2) deletions that could be found only in tcdA. Characteristic differences between strains were mainly focused to the 5′ third of tcdB (B1 fragment) and/or the 3′ third of tcdA (A3 fragment). The possible use of our approach for typing of C. difficile toxin genes is discussed.
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…
Patterns of puffing activity and chromosomal polymorphism in Drosophila subobscura : 3. Puffing activity depression by inbreeding.
1984
The effect of inbreeding on the puffing patterns of polytene chromosomes of Drosophila subobscura was analysed. Puffing activity was studied in two strains of D. subobscura: one which had been subject to inbreeding for 288 generations, and in the hybrids from a cross between them. A strong overall decrease in puffing activity was found in the inbred line. In general, hybrids behaved in a similar way to the inbred line or showed activity intermediate between the two lines. The fertility and viability of the two homozygous lines and of the hybrids were also determined. These parameters of fitness are very low in the inbred line. Hybrids displayed intermediate behaviour.
A report of an international collaborative experiment to demonstrate the uniformity obtainable using DNA profiling techniques
1992
This paper describes a collaborative exercise intended to demonstrate whether uniformity of DNA profile results could be achieved between different European laboratories. It was shown that this goal can be obtained provided that a common protocol is followed (specifically the use of a common electrophoretic buffer as being the most important parameter). Generally, lower molecular weight loci (with lower molecular weight fragments) such as YNH24 perform better than higher molecular weight loci such as MS43a. The results of the exercise are discussed in relation to the objectives of the European DNA profiling group (EDNAP).
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.
Polymorphism and chromosomal localization of the porcine signal transducer and activator of transcription 5B gene (STAT5B).
2006
Signal transducers and activators of transcription (STATs) are a family of transcription factors. STAT5A and 5B are two highly related proteins encoded by two distinct genes. Transgenic knockout mice studies have indicated the importance of STAT5 proteins for the regulation of both lactation and growth performance. Moreover, different studies determine the role of STAT5 proteins in the modulation of adipocyte function. In this study, we sequenced one fragment of STAT5B gene from animals of six breeds (Duroc, Iberian, Landrace, Large White, Pie´train and Meishan) to identify genetic variants. A G/A single nucleotide polymorphism in intron 14 creates a polymorphic PstI restriction site and wa…
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…
Detection of a novel germline mutation in the von Hippel-Lindau tumour-suppressor gene by fluorescence-labelled base excision sequence scanning (F-BE…
1999
The von Hippel Lindau (VHL) syndrome is an inherited multi-tumour disorder characterised by clinical heterogeneity and high penetrance. The VHL gene has been shown to be a tumour-suppressor gene. A carrier of a germline mutation will be predisposed to a high variety of benign and malign tumours affecting different organ systems. As treatment of VHL malformations in presymptomatic stages will improve significantly the clinical outcome and the patient's quality of life, early and unambiguous detection of a germline mutation is mandatory. Direct sequencing especially of large genes might be laborious and time consuming. Therefore, most laboratories apply single strand conformational polymorphi…