Search results for "single-nucleotide polymorphism"

Preselection statistics and Random Forest classification identify population informative single nucleotide polymorphisms in cosmopolitan and autochth…

2018

Commercial single nucleotide polymorphism (SNP) arrays have been recently developed for several species and can be used to identify informative markers to differentiate breeds or populations for several downstream applications. To identify the most discriminating genetic markers among thousands of genotyped SNPs, a few statistical approaches have been proposed. In this work, we compared several methods of SNPs preselection (Delta, F st and principal component analyses (PCA)) in addition to Random Forest classifications to analyse SNP data from six dairy cattle breeds, including cosmopolitan (Holstein, Brown and Simmental) and autochthonous Italian breeds raised in two different regions and …

Full-length sequencing and identification of novel polymorphisms in the ACACA gene of Valle del Belice sheep breed

2017

The essential role of the acetyl-CoA carboxylase (ACACA) enzyme in milk fatty acid (FA) synthesis suggests that it may be responsible for the phenotypic variability observed in milk. Before attempting association analyses between this gene and/or enzyme and phenotypic traits, a study on the genetic variability within this locus is required. The aim of this work was to sequence the entire coding region of ACACA gene in Valle del Belice sheep breed to identify polymorphic sites. A total of 51 coding exons of ACACA gene were sequenced in 32 individuals of Valle del Belice sheep breed. Sequencing analysis and alignment of obtained sequences showed the presence of 23 polymorphic sites. The most …

A low-frequency haplotype spanning SLX4/FANCP constitutes a new risk locus for early-onset breast cancer (<60 years) and is associated with reduce…

2017

Only a fraction of breast cancer (BC) cases can be yet explained by mutations in genes or genomic variants discovered in linkage, genome-wide association and sequencing studies. The known genes entailing medium or high risk for BC are strongly enriched for a function in DNA double strand repair. Thus, aiming at identifying low frequency variants conferring an intermediate risk, we here investigated 17 variants (MAF: 0.01-0.1) in 10 candidate genes involved in DNA repair or cell cycle control. In an exploration cohort of 437 cases and 1189 controls, we show the variant rs3810813 in the SLX4/FANCP gene to be significantly associated with both BC (≤60 years; OR = 2.6(1.6-3.9), p = 1.6E-05) and…

2020

Lipoprotein(a) [Lp(a)] is a major cardiovascular risk factor, which is largely genetically determined by one major gene locus, the LPA gene. Many aspects of the transcriptional regulation of LPA are poorly understood and the role of epigenetics has not been addressed yet. Therefore, we conducted an epigenome-wide analysis of DNA methylation on Lp(a) levels in two population-based studies (total n = 2208). We identified a CpG site in the LPA promoter which was significantly associated with Lp(a) concentrations. Surprisingly, the identified CpG site was found to overlap the SNP rs76735376. We genotyped this SNP de-novo in three studies (total n = 7512). The minor allele of rs76735376 (1.1% mi…

Genomic signatures of local adaptation to the degree of environmental predictability in rotifers

2018

AbstractEnvironmental fluctuations are ubiquitous and thus essential for the study of adaptation. Despite this, genome evolution in response to environmental fluctuations —and more specifically to the degree of environmental predictability– is still unknown. Saline lakes in the Mediterranean region are remarkably diverse in their ecological conditions, which can lead to divergent local adaptation patterns in the inhabiting aquatic organisms. The facultatively sexual rotifer Brachionus plicatilis shows diverging local adaptation in its life-history traits in relation to estimated environmental predictability in its habitats. Here, we used an integrative approach —combining environmental, phe…

Exome-Wide Association Study on Alanine Aminotransferase Identifies Sequence Variants in the GPAM and APOE Associated With Fatty Liver Disease.

2021

BACKGROUND & AIMS: Fatty liver disease (FLD) is a growing epidemic that is expected to be the leading cause of end-stage liver disease within the next decade. Both environmental and genetic factors contribute to the susceptibility of FLD. Several genetic variants contributing to FLD have been identified in exome-wide association studies. However, there is still a missing hereditability indicating that other genetic variants are yet to be discovered. METHODS: To find genes involved in FLD, we first examined the association of missense and nonsense variants with alanine amino transferase at an exome-wide level in 425,671 participants from the UK Biobank. We then validated genetic variants wit…

The first high-density sequence characterized SNP-based linkage map of olive (Olea europaea L. subsp. europaea) developed using genotyping by sequenc…

2016

A number of linkage maps have been previously developed in olive; however, these are mostly composed of markers that have not been characterized at the sequence level, supplemented with smaller numbers of microsatellite markers. In this investigation, we sought to develop a saturated linkage mapping resource for olive composed entirely of sequence characterized markers. We employed genotyping by sequencing to develop a map of a F2 population derived from the selfing of the cultivar Koroneiki. The linkage map contained a total of 23 linkage groups comprised of 1,597 tagged SNP markers in 636 mapping bins spanning a genetic distance of 1189.7 cM. An additional 6,658 segregating SNPs were asso…

2018

Genome-Wide-Association-Studies have become a powerful method to link point mutations (e.g. single nucleotide polymorphisms (SNPs)) to a certain phenotype or a disease. However, their power to detect SNPs associated to polygenic diseases such as Alzheimer's Disease (AD) is limited, since they can only infer the pairwise relation of single SNPs to the phenotype and ignore possible effects of various SNP combinations. The common method to probe these possible complex genetic patterns is to compute a measure called linkage disequilibrium (LD). Despite the fact that several predictive patterns found with LD could successfully be applied to medical diagnosis, this measure still holds several dra…

The rs11187533 C>T Variant of the <b><i>FFAR4</i></b> Gene Is Associated with Lower Levels of Fasting Glucose and De…

2020

<b><i>Introduction:</i></b> Genetic factors can modulate the development of associated comorbidities in obesity. It has been shown that loss-of-function variants of the <i>free fatty acid receptor 4 (FFAR4)</i> gene negatively affect obesity comorbidities such as insulin resistance and fatty liver disease. <b><i>Objective:</i></b> To test the relationships of metabolic factors in children with obesity with variants of the <i>FFAR4</i> gene. <b><i>Methods:</i></b> We performed an association study of 3 single nucleotide polymorphisms (SNPs) of <i>FFAR4</i> (rs10882273 T>C, rs1…

New insights into the genetic component of non-infectious uveitis through an Immunochip strategy.

2016

BACKGROUND: Large-scale genetic studies have reported several loci associated with specific disorders involving uveitis. Our aim was to identify genetic risk factors that might predispose to uveitis per se, independent of the clinical diagnosis, by performing a dense genotyping of immune-related loci.METHODS: 613 cases and 3693 unaffected controls from three European case/control sets were genotyped using the Immunochip array. Only patients with non-infectious non-anterior uveitis and without systemic features were selected. To perform a more comprehensive analysis of the human leucocyte antigen (HLA) region, SNPs, classical alleles and polymorphic amino acid variants were obtained via impu…