Population-specific causal disease effect sizes in functionally important regions impacted by selection.

Many diseases exhibit population-specific causal effect sizes with trans-ethnic genetic correlations significantly less than 1, limiting trans-ethnic polygenic risk prediction. We develop a new method, S-LDXR, for stratifying squared trans-ethnic genetic correlation across genomic annotations, and apply S-LDXR to genome-wide summary statistics for 31 diseases and complex traits in East Asians (average N = 90K) and Europeans (average N = 267K) with an average trans-ethnic genetic correlation of 0.85.

Multi-trait association studies discover pleiotropic loci between Alzheimer's disease and cardiometabolic traits.

Background: Identification of genetic risk factors that are shared between Alzheimer's disease (AD) and other traits, i.e., pleiotropy, can help improve our understanding of the etiology of AD and potentially detect new therapeutic targets.

The relationship between circulating lipids and breast cancer risk: A Mendelian randomization study.

Background: A number of epidemiological and genetic studies have attempted to determine whether levels of circulating lipids are associated with risks of various cancers, including breast cancer (BC). However, it remains unclear whether a causal relationship exists between lipids and BC. If alteration of lipid levels also reduced risk of BC, this could present a target for disease prevention.

Cross-trait analyses with migraine reveal widespread pleiotropy and suggest a vascular component to migraine headache.

Background: Nearly a fifth of the world's population suffer from migraine headache, yet risk factors for this disease are poorly characterized.

Methods: To further elucidate these factors, we conducted a genetic correlation analysis using cross-trait linkage disequilibrium (LD) score regression between migraine headache and 47 traits from the UK Biobank. We then tested for possible causality between these phenotypes and migraine, using Mendelian randomization.

BetaScan2: Standardized Statistics to Detect Balancing Selection Utilizing Substitution Data.

Long-term balancing selection results in a build-up of alleles at similar frequencies and a deficit of substitutions when compared with an outgroup at a locus. The previously published β(1) statistics detect balancing selection using only polymorphism data. We now propose the β(2) statistic which detects balancing selection using both polymorphism and substitution data.

Bivariate Genome-Wide Association Scan Identifies 6 Novel Loci Associated With Lipid Levels and Coronary Artery Disease.

Background: Plasma lipid levels are heritable and genetically associated with risk of coronary artery disease (CAD). However, genome-wide association studies (GWAS) routinely analyze these traits independent of one another. Joint GWAS for two related phenotypes can lead to a higher powered analysis to detect variants contributing to both traits.

Detecting Long-Term Balancing Selection Using Allele Frequency Correlation.

Balancing selection occurs when multiple alleles are maintained in a population, which can result in their preservation over long evolutionary time periods. A characteristic signature of this long-term balancing selection is an excess number of intermediate frequency polymorphisms near the balanced variant. However, the expected distribution of allele frequencies at these loci has not been extensively detailed, and therefore existing summary statistic methods do not explicitly take it into account.

Serum calcium and risk of migraine: a Mendelian randomization study.

Migraine affects ∼14% of the world's population, though not all predisposing causal risk factors are known. We used electronic health records, genetic co-heritability analysis, and a two-sample Mendelian Randomization (MR) design to determine if elevated serum calcium levels were associated with risk of migraine headache. Co-morbidity was evaluated using electronic health records obtained from the PennOmics database comprising >1 million patient entries.

Event inference in multidomain families with phylogenetic reconciliation.

Background: Reconstructing evolution provides valuable insights into the processes of gene evolution and function. However, while there have been great advances in algorithms and software to reconstruct the history of gene families, these tools do not model the domain shuffling events (domain duplication, insertion, transfer, and deletion) that drive the evolution of multidomain protein families. Protein evolution through domain shuffling events allows for rapid exploration of functions by introducing new combinations of existing folds.

A customized Web portal for the genome of the ctenophore Mnemiopsis leidyi.

Background: Mnemiopsis leidyi is a ctenophore native to the coastal waters of the western Atlantic Ocean. A number of studies on Mnemiopsis have led to a better understanding of many key biological processes, and these studies have contributed to the emergence of Mnemiopsis as an important model for evolutionary and developmental studies. Recently, we sequenced, assembled, annotated, and performed a preliminary analysis on the 150-megabase genome of the ctenophore, Mnemiopsis.