Search results for "Association studies"
showing 10 items of 216 documents
Genetic background in nonalcoholic fatty liver disease: A comprehensive review
2015
In the Western world, nonalcoholic fatty liver disease (NAFLD) is considered as one of the most significant liver diseases of the twenty-first century. Its development is certainly driven by environmental factors, but it is also regulated by genetic background. The role of heritability has been widely demonstrated by several epidemiological, familial, and twin studies and case series, and likely reflects the wide inter-individual and inter-ethnic genetic variability in systemic metabolism and wound healing response processes. Consistent with this idea, genome-wide association studies have clearly identified Patatin-like phosholipase domain-containing 3 gene variant I148M as a major player i…
Molecular and clinical characterization of a small duplication Xp in a human female with psychiatric disorders
2011
CGH techniques allow us to detect small duplications thatoccur in humans with phenotypic manifestations and demon-strate the importance of these duplications in the etiologyof neurodevelopmental impairment. As in the case of otherX-linked disorders, X-inactivation plays a major role in theclinical expression of such X chromosomal imbalances withusually milder symptoms in females than in males. Mostmale patients carrying Xp duplication have mental retarda-tion (X-linked mental retardation) and variable facial dys-morphic features (Gimelli
Genome-wide association analysis on normal hearing function identifies PCDH20 and SLC28A3 as candidates for hearing function and loss.
2015
Hearing loss and individual differences in normal hearing both have a substantial genetic basis. Although many new genes contributing to deafness have been identified, very little is known about genes/variants modulating the normal range of hearing ability. To fill this gap, we performed a two-stage meta-analysis on hearing thresholds (tested at 0.25, 0.5, 1, 2, 4, 8 kHz) and on pure-tone averages (low-, medium-and high-frequency thresholds grouped) in several isolated populations from Italy and Central Asia (total N = 2636). Here, we detected two genome-wide significant loci close to PCDH20 and SLC28A3 (top hits: rs78043697, P = 4.71E-10 and rs7032430, P = 2.39E-09, respectively). For both…
openSNP–A Crowdsourced Web Resource for Personal Genomics
2014
Genome-Wide Association Studies are widely used to correlate phenotypic traits with genetic variants. These studies usually compare the genetic variation between two groups to single out certain Single Nucleotide Polymorphisms (SNPs) that are linked to a phenotypic variation in one of the groups. However, it is necessary to have a large enough sample size to find statistically significant correlations. Direct-To-Consumer (DTC) genetic testing can supply additional data: DTC-companies offer the analysis of a large amount of SNPs for an individual at low cost without the need to consult a physician or geneticist. Over 100,000 people have already been genotyped through Direct-To-Consumer genet…
Identification and characterization of novel associations in the CASP8/ALS2CR12 region on chromosome 2 with breast cancer risk.
2014
Previous studies have suggested that polymorphisms in CASP8 on chromosome 2 are associated with breast cancer risk. To clarify the role of CASP8 in breast cancer susceptibility, we carried out dense genotyping of this region in the Breast Cancer Association Consortium (BCAC). Single-nucleotide polymorphisms (SNPs) spanning a 1 Mb region around CASP8 were genotyped in 46 450 breast cancer cases and 42 600 controls of European origin from 41 studies participating in the BCAC as part of a custom genotyping array experiment (iCOGS). Missing genotypes and SNPs were imputed and, after quality exclusions, 501 typed and 1232 imputed SNPs were included in logistic regressionmodels adjusting for stud…
Associations between sports participation, cardiorespiratory fitness, and adiposity in young adult twins.
2011
Exercise behavior, cardiorespiratory fitness, and obesity are strongly influenced by genetic factors. By studying young adult twins, we examined to what extent these interrelated traits have shared genetic and environmental etiologies. We studied 304 twin individuals selected from the population-based FinnTwin16 study. Physical activity was assessed with the Baecke questionnaire, yielding three indexes: sport index, leisure-time index, and work index. In this study, we focused on sport index, which describes sports participation. Body composition was determined using dual-energy X-ray absorptiometry and cardiorespiratory fitness using a bicycle ergometer exercise test with gas exchange ana…
Relation Between Genetic Factors and Frailty in Older Adults.
2018
Frailty is a geriatric syndrome that identifies individuals at higher risk of disability, institutionalization, and death. We previously reported that frailty is related to oxidative stress and cognitive impairment-related biomarkers. The aim of this study was to determine whether frailty is associated with genetic variants.Longitudinal population-based cohort of 2488 community-dwelling people from Toledo, Spain, aged 65 years or older.We obtained blood samples from 78 individuals with frailty and 74 nonfrail individuals who were nonfrail (according to Fried criteria) from the Toledo Study of Healthy Ageing and extracted DNA using the Chemagic DNA blood kit.Sample genotyping was carried out…
Array-CGH and clinical characterization in a patient with subtelomeric 6p deletion without ocular dysgenesis
2011
Subtelomeric terminal 6p deletion has been recognized as a clinically identifiable syndrome including facial dysmorphism, malformation of the anterior eye chamber, hearing loss, heart defect and developmental delay. Genotype –phenotype correlations of previously published patients have been strongly suggested anterior eye segment anomalies as one of major malformation of the syndrome if the critical 6p25 region containing the FOXC 1 gene. In addition it has been hypothesized the presence in this region of one or more genes involved in hearing loss. We report on a case of terminal 6p deletion in a 47, XYY karyotype. Further characterization of the deletion with array comparative genome hybri…
Testing for goodness rather than lack of fit of an X–chromosomal SNP to the Hardy-Weinberg model
2019
The problem of checking the genotype distribution obtained for some diallelic marker for compatibility with the Hardy-Weinberg equilibrium (HWE) condition arises also for loci on the X chromosome. The possible genotypes depend on the sex of the individual in this case: for females, the genotype distribution is trinomial, as in the case of an autosomal locus, whereas a binomial proportion is observed for males. Like in genetic association studies with autosomal SNPs, interest is typically in establishing approximate compatibility of the observed genotype frequencies with HWE. This requires to replace traditional methods tailored for detecting lack of fit to the model with an equivalence test…
Fertility Relevance Probability Analysis Shortlists Genetic Markers for Male Fertility Impairment.
2020
Impairment of male fertility is one of the major public health issues worldwide. Nevertheless, genetic causes of male sub- and infertility can often only be suspected due to the lack of reliable and easy-to-use routine tests. Yet, the development of a marker panel is complicated by the large quantity of potentially predictive markers. Actually, hundreds or even thousands of genes could have fertility relevance. Thus, a systematic method enabling a selection of the most predictive markers out of the many candidates is required. As a criterion for marker selection, we derived a gene-specific score, which we refer to as fertility relevance probability (FRP). For this purpose, we first categori…