Search results for " polymorphism"
showing 10 items of 1028 documents
Screening of hereditary spastic paraplegia patients for alterations at NIPA1 mutational hotspots.
2008
Item does not contain fulltext Mutations in NIPA1 cause hereditary spastic paraplegia type 6 (SPG6 HSP). Sequencing of the whole gene has revealed alterations of either of two nucleotides in eight of nine SPG6 HSP families reported to date. By analysing CpG methylation, we provide a mechanistic explanation for a mutational hotspot to underlie frequent alteration of one of these nucleotides. We also developed PCR RFLP assays to detect recurrent NIPA1 changes and screened 101 independent HSP patients, including 45 index patients of autosomal dominant HSP families. Our negative finding in this cohort for which several other causes of HSP had been excluded suggests NIPA1 alterations at mutation…
Ancient Haplotypes at the 15q24.2 Microdeletion Region Are Linked to Brain Expression of MAN2C1 and Children's Intelligence
2016
The chromosome bands 15q24.1-15q24.3 contain a complex region with numerous segmental duplications that predispose to regional microduplications and microdeletions, both of which have been linked to intellectual disability, speech delay and autistic features. The region may also harbour common inversion polymorphisms whose functional and phenotypic manifestations are unknown. Using single nucleotide polymorphism (SNP) data, we detected four large contiguous haplotype-genotypes at 15q24 with Mendelian inheritance in 2,562 trios, African origin, high population stratification and reduced recombination rates. Although the haplotype-genotypes have been most likely generated by decreased or abse…
Effects of BRCA2 cis-regulation in normal breast and cancer risk amongst BRCA2 mutation carriers
2012
Introduction: Cis-acting regulatory single nucleotide polymorphisms (SNPs) at specific loci may modulate penetrance of germline mutations at the same loci by introducing different levels of expression of the wild-type allele. We have previously reported that BRCA2 shows differential allelic expression and we hypothesize that the known variable penetrance of BRCA2 mutations might be associated with this mechanism. Methods: We combined haplotype analysis and differential allelic expression of BRCA2 in breast tissue to identify expression haplotypes and candidate cis-regulatory variants. These candidate variants underwent selection based on in silico predictions for regulatory potential and di…
Population structure and mitochondrial DNA gene flow in Old World populations of Drosophila subobscura
1992
An extensive survey of mitochondrial DNA (mtDNA) restriction polymorphism in 156 isofemale lines from 29 different geographic populations of Drosophila subobscura distributed throughout the Old World was carried out. Ten restriction enzymes were used, five of which revealed restriction site polymorphism. Of the 31 restriction sites detected, 13 were found to be polymorphic. Comparisons with the mtDNA map of Drosophila yakuba indicate that the variable sites are mainly concentrated in protein genes, especially those corresponding to the NADH complex. A total of 13 different haplotypes were observed, two of which (haplotypes I and II) are quite frequent and widely distributed throughout the p…
Association Between Exercise and Pubertal BMD Is Modulated by Estrogen Receptor α Genotype
2003
Genetic and environmental factors contribute to bone mass, but the ways they interact remain poorly understood. This study of 245 pre- and early pubertal girls found that the PvuII polymorphism in the ER- gene modulates the effect of exercise on BMD at loaded bone sites. Introduction: Impaired achievement of bone mass at puberty is an important risk factor for the development of osteoporosis in later life. Genetic, as well as environmental, factors contribute to bone mass, but the ways they interact with each other remain poorly understood. Materials and Methods: We investigated the interaction between a PvuII polymorphism at the ER- gene and physical activity (PA) on the modulation of bone…
Genetic Determined Downregulation of Both Type 1 and Type 2 Cytokine Pathways Might Be Protective against Pancreatic Cancer
2009
Many cytokine polymorphisms have been studied for associations with susceptibility to breast, gastric, liver, lung, prostate, and ovarian cancer without conclusive results. The cytokine network, indeed, is characterized by complex interactions, and the final biological effect of a single genetic variation depends on the balance among different molecular signals. As is well known, Th1/Th2 cytokine unbalanced production might predispose to different pathologies, cancer included. In general, a prolonged type 1 inflammatory response might allow that cells accumulating enough "genetic hits" are promoted to neoplastic transformation. On the other hand, IL-13-producing cells through the IL-13/IL-4…
Inbreeding does not alter the response to an experimental heat wave in a freshwater snail
2019
Global climate change affects natural populations of many species by increasing the average temperature and the frequency of extreme weather events (e.g. summer heat waves). The ability of organisms to cope with these environmental changes can, however, depend on their genetic properties. For instance, genetic load owing to inbreeding could alter organisms’ responses to climate change-mediated environmental changes but such effects are often overlooked. We investigated the effects of an experimental heat wave (25°C versus 15°C) on life history (reproduction, size) and constitutive immune defence traits (phenoloxidase-like and antibacterial activity of haemolymph) in relation to inbreeding b…
Characterization of Gibberella fujikuroi complex isolates by fumonisin B-1 and B-2 analysis and by RAPD and restriction analysis of PCR-amplified int…
2000
Summary Twenty nine isolates of Fusarium spp. (twenty four of them belonging to the Gibberella fujikuroi complex) isolated from banana and corn from different geographical regions were analyzed for their ability to produce fumonisins B 1 and B 2 and for genetic relatedness using random amplified polymorphic DNA (RAPD) and restriction analysis of PCR amplification products of the 5.8s ribosomal DNA-intervening internal transcribed spacer regions (ITS I-5.8S-ITS II). For RAPD analysis, six of twenty oligonucleotide primers were selected after testing with five Fusarium spp. isolates and used to characterize 24 additional isolates. DNA fragments from the 29 isolates of Fusarium spp., which wer…
Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption
2015
Contains fulltext : 155360.pdf (Publisher’s version ) (Closed access) Coffee, a major dietary source of caffeine, is among the most widely consumed beverages in the world and has received considerable attention regarding health risks and benefits. We conducted a genome-wide (GW) meta-analysis of predominately regular-type coffee consumption (cups per day) among up to 91,462 coffee consumers of European ancestry with top single-nucleotide polymorphisms (SNPs) followed-up in ~30 062 and 7964 coffee consumers of European and African-American ancestry, respectively. Studies from both stages were combined in a trans-ethnic meta-analysis. Confirmed loci were examined for putative functional and b…
Yeast ecology of vineyards within Marsala wine area (western Sicily) in two consecutive vintages and selection of autochthonous Saccharomyces cerevis…
2012
In this work, the yeast ecology associated with the spontaneous fermentation of Grillo cultivar grapes from 10 vineyards was analyzed from grape harvest till complete consumption of must sugars. The microbiological investigation started with the plate count onto two culture media to distinguish total yeasts (TY) and presumptive Saccharomyces (PS). Yeasts were randomly isolated and identified by a combined genotypic approach consisting of restriction fragment length polymorphism (RFLP) of 5.8S rRNA gene and 26S rRNA and sequencing of D1/D2 domain of the 26S rRNA gene, which resulted in the recognition of 14 species belonging to 10 genera. The distribution of the yeasts within the vineyards s…