Mendelian Randomization versus Path Models: Making Causal Inferences in Genetic Epidemiology
Conclusions: Mendelian randomization and path models use different concepts for causal inference. Path modeling but not simple Mendelian randomization analysis is well suited to study causality with different levels of ‘omics' data.Hum Hered 2015;79:194-204 (Source: Human Heredity)
Source: Human Heredity - July 22, 2015 Category: Genetics & Stem Cells Source Type: research
A Bagged, Partially Linear, Tree-Based Regression Procedure for Prediction and Variable Selection
Conclusion: The proposed bagged GPLTR procedure performs well for prediction and variable selection.Hum Hered 2015;79:182-193 (Source: Human Heredity)
Source: Human Heredity - July 22, 2015 Category: Genetics & Stem Cells Source Type: research
Multivariate Quantitative Multifactor Dimensionality Reduction for Detecting Gene-Gene Interactions
Conclusions: The Multi-QMDR approach improves the performance of QMDR when multiple quantitative phenotypes are available.Hum Hered 2015;79:168-181 (Source: Human Heredity)
Source: Human Heredity - July 22, 2015 Category: Genetics & Stem Cells Source Type: research
Model-Based Multifactor Dimensionality Reduction for Rare Variant Association Analysis
Genome-wide association studies have revealed a vast amount of common loci associated to human complex diseases. Still, a large proportion of heritability remains unexplained. The extent to which rare genetic variants (RVs) are able to explain a relevant portion of the genetic heritability for complex traits leaves room for several debates and paves the way to the collection of RV databases and the development of novel analytic tools to analyze these. To date, several statistical methods have been proposed to uncover the association of RVs with complex diseases, but none of them is the clear winner in all possible scenario...
Source: Human Heredity - July 22, 2015 Category: Genetics & Stem Cells Source Type: research
A Statistical Method for Identifying Trait-Associated Copy Number Variants
Copy number variants (CNVs), ranging in size from about one kilobase to several megabases, are DNA alterations of a genome that result in the cell having less or more than two copies of segments of the DNA. Such CNVs have been shown to be associated with many complex phenotypes, ranging from diseases to gene expressions. Novel methods have been developed for identifying CNVs both at the individual and at the population level. However, methods for testing CNV association are limited. Most available methods employ a two-step approach, where CNVs carried by the samples are identified first and then tested for association. How...
Source: Human Heredity - July 22, 2015 Category: Genetics & Stem Cells Source Type: research
Leveraging Epidemiologic and Clinical Collections for Genomic Studies of Complex Traits
Conclusion: Little bias is observed among health metrics, suggesting this clinical collection is suitable for genomic studies along with traditional epidemiologic cohorts.Hum Hered 2015;79:137-146 (Source: Human Heredity)
Source: Human Heredity - July 22, 2015 Category: Genetics & Stem Cells Source Type: research
Framework for the Integration of Genomics, Epigenomics and Transcriptomics in Complex Diseases
Conclusions: The proposed integrative framework allowed us to identify relationships at the whole-genome level providing some new biological insights and highlighting the importance of integrating -omics data.Hum Hered 2015;79:124-136 (Source: Human Heredity)
Source: Human Heredity - July 22, 2015 Category: Genetics & Stem Cells Source Type: research
Global Individual Ancestry Using Principal Components for Family Data
Studies of complex human diseases and traits associated with candidate genes are potentially vulnerable to bias (confounding) due to population stratification and inbreeding, especially in admixed population. In GWAS, the principal components (PCs) method provides a global ancestry value per subject, allowing corrections for population stratification. However, these coefficients are typically estimated assuming unrelated individuals, and if family structure is present and ignored, such substructures may induce artifactual PCs. Extensions of the PCs method have been proposed by Konishi and Rao [Biometrika 1992;79:631-641], ...
Source: Human Heredity - July 9, 2015 Category: Genetics & Stem Cells Source Type: research
Integrating Multiple Correlated Phenotypes for Genetic Association Analysis by Maximizing Heritability
Many correlated disease variables are analyzed jointly in genetic studies in the hope of increasing power to detect causal genetic variants. One approach involves assessing the relationship between each phenotype and each SNP individually and using a Bonferroni correction for the effective number of tests conducted. Alternatively, one can apply a multivariate regression or a dimension reduction technique, such as principal component analysis, and test for the association with the principal components of the phenotypes rather than the individual phenotypes. Inspired by the previous approaches of combining phenotypes to maxi...
Source: Human Heredity - June 20, 2015 Category: Genetics & Stem Cells Source Type: research
A Generalized Sequential Bonferroni Procedure for GWAS in Admixed Populations Incorporating Admixture Mapping Information into Association Tests
Conclusion: The smooth-GSB procedure can result in a better performance than several existing methods for GWAS in admixed populations.Hum Hered 2015;79:80-92 (Source: Human Heredity)
Source: Human Heredity - June 15, 2015 Category: Genetics & Stem Cells Source Type: research
A Bayesian Partitioning Model for the Detection of Multilocus Effects in Case-Control Studies
Conclusion: We demonstrate that our approach has better power to detect multilocus interactions than several existing approaches. When applied to the ARIC study dataset with 9,328 individuals to study gene-based associations for type 2 diabetes, our method identified some novel variants not detected by conventional single-locus association analyses.Hum Hered 2015;79:69-79 (Source: Human Heredity)
Source: Human Heredity - June 2, 2015 Category: Genetics & Stem Cells Source Type: research
A Sequence Kernel Association Test for Dichotomous Traits in Family Samples under a Generalized Linear Mixed Model
Conclusion: We propose a set-based association test that can be used to analyze family data with dichotomous phenotypes while handling genetic variants with the same or opposite directions of effects as well as any types of family relationships.Hum Hered 2015;79:60-68 (Source: Human Heredity)
Source: Human Heredity - March 11, 2015 Category: Genetics & Stem Cells Source Type: research
43rd European Mathematical Genetics Meeting (EMGM) 2015. April 16-17, 2015, Brest, France: Abstracts
Hum Hered 2015;79:28-52 (Source: Human Heredity)
Source: Human Heredity - March 11, 2015 Category: Genetics & Stem Cells Source Type: research
Molecular Genetic Evidence for Shared Etiology of Autism and Prodigy
Child prodigies are rare individuals with an exceptional working memory and unique attentional skills that may facilitate the attainment of professional skill levels at an age well before what is observed in the general population. Some characteristics of prodigy have been observed to be quantitatively similar to those observed in autism spectrum disorder (ASD), suggesting possible shared etiology, though objectively validated prodigies are so rare that evidence has been sparse. We performed a family-based genome-wide linkage analysis on 5 nuclear and extended families to search for genetic loci that influence the presence...
Source: Human Heredity - March 9, 2015 Category: Genetics & Stem Cells Source Type: research
The Role of Rare Variants in Systolic Blood Pressure: Analysis of ExomeChip Data in HyperGEN African Americans
Cardiovascular diseases are among the most significant health problems in the United States today, with their major risk factor, hypertension, disproportionately affecting African Americans (AAs). Although GWAS have identified dozens of common variants associated with blood pressure (BP) and hypertension in European Americans, these variants collectively explain (Source: Human Heredity)
Source: Human Heredity - March 6, 2015 Category: Genetics & Stem Cells Source Type: research
