Publications by authors named "Sebastian Zollner"

Polygenic risk scores (PRSs) depend on genetic ancestry due to differences in allele frequencies between ancestral populations. This leads to implementation challenges in diverse populations. We propose a framework to calibrate PRS based on ancestral makeup.

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In studies of individuals of primarily European genetic ancestry, common and low-frequency variants and rare coding variants have been found to be associated with the risk of bipolar disorder (BD) and schizophrenia (SZ). However, less is known for individuals of other genetic ancestries or the role of rare non-coding variants in BD and SZ risk. We performed whole genome sequencing of African American individuals: 1,598 with BD, 3,295 with SZ, and 2,651 unaffected controls (InPSYght study).

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  • The A allele of rs334 in the β-globin gene significantly predicts pneumonia in African American adults, and this study explores its impact on African American children.
  • Genome-wide association analyses were conducted on 482 children with pneumonia and 2,048 controls, revealing rs334 as the most significant variant when using imputed genotypes from a specific reference panel.
  • The findings suggest that, like in adults, genetic variations in the β-globin locus that increase the risk for sickle cell disease are also the strongest predictors of pneumonia in African American children.
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  • Spatial transcriptomics (ST) technologies allow for in-depth gene expression analysis at a very fine scale, but traditional methods face challenges due to complex tissue structures and irregular cell shapes.
  • The new method, FICTURE, offers a segmentation-free approach that can analyze large-scale transcriptome data with submicron precision, making it compatible with different types of ST data.
  • FICTURE is significantly more efficient than existing methods and improves our understanding of intricate tissue architectures in challenging areas like vascular and fibrotic tissues, enhancing the exploration of high-resolution spatial transcriptomics.
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  • Venous thromboembolism (VTE) poses significant health risks, with a notable difference in incidence rates between Black and White Americans.
  • Researchers developed polygenic risk scores (PRSs) for VTE using data from both European and African-ancestry populations to enhance predictive capability.
  • Results showed that multi-ancestry PRSs slightly outperformed ancestry-specific ones in predicting VTE risk, indicating potential benefits in using diverse data for better risk assessment across populations.
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Polygenic risk scores (PRS) are summaries of an individual's personalized genetic risk for a trait or disease. However, PRS often perform poorly for phenotype prediction when the ancestry of the target population does not match the population in which GWAS effect sizes were estimated. For many populations this can be addressed by performing GWAS in the target population.

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  • Type 2 diabetes (T2D) is a complex disease influenced by various genetic factors and molecular mechanisms that vary by cell type and ancestry.
  • In a large study involving over 2.5 million individuals, researchers identified 1,289 significant genetic associations linked to T2D, including 145 new loci not previously reported.
  • The study categorized T2D signals into eight distinct clusters based on their connections to cardiometabolic traits and showed that these genetic profiles are linked to vascular complications, emphasizing the role of obesity-related processes across different ancestry groups.
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  • A genome-wide association study was conducted on thyroid function, analyzing data from up to 271,040 European individuals, focusing on hormones like TSH, FT4, and T3.
  • The study identified 259 significant genetic associations for TSH (61% were novel), and notable findings for FT4 and T3, indicating that specific genes influence thyroid hormone levels and metabolism.
  • The research findings enhance the understanding of thyroid hormone roles and suggest that variations in thyroid function may impact various health conditions including cardiovascular issues, autoimmune diseases, and cancer.
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  • Venous thromboembolism (VTE) significantly affects health outcomes and shows disparities in incidence between Black and White Americans, necessitating improved risk assessment methods.* -
  • Polygenic risk scores (PRSs) derived from diverse ancestry data performed better than traditional PRSs, indicating their potential for accurately identifying high-risk individuals for VTE in both European and African ancestries.* -
  • The study found that using multi-ancestry PRSs could enhance risk stratification, with individuals in the highest risk category having a substantially increased likelihood of VTE, suggesting a path towards personalized treatment approaches.*
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Spatial transcriptomics (ST) technologies have advanced to enable transcriptome-wide gene expression analysis at submicron resolution over large areas. Analysis of high-resolution ST data relies heavily on image-based cell segmentation or gridding, which often fails in complex tissues due to diversity and irregularity of cell size and shape. Existing segmentation-free analysis methods scale only to small regions and a small number of genes, limiting their utility in high-throughput studies.

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  • A recent study analyzed genetic data from over 156,000 prostate cancer cases and 788,000 controls from diverse populations, significantly increasing the representation of non-European participants.
  • Researchers identified 187 new genetic risk variants for prostate cancer, bringing the total to 451, enhancing understanding of genetic factors across different ancestries.
  • The developed genetic risk score (GRS) showed varying risk levels for prostate cancer among different ancestry groups, highlighting its potential for better risk assessment, especially in men of African descent.
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  • The Mexico City Prospective Study is a large-scale research initiative involving over 150,000 adults from urban areas in Mexico City, aimed at understanding genetic diversity and ancestry.
  • The study reveals a mix of Indigenous American, European, and African ancestries among participants, highlighting significant genetic differences and a unique genetic landscape within the Indigenous Mexican population.
  • Researchers created a valuable reference panel for genetic research, improving the accuracy of studying genetic variants in populations with high Indigenous ancestry, and providing essential resources for future genetic studies in both Mexico and the US.
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  • Obesity poses a significant public health challenge and is linked to high mortality rates, with prior studies focusing mostly on European populations.
  • This research utilized whole-genome sequencing data from a diverse group of 88,873 individuals, finding 18 new signals associated with body mass index (BMI) and highlighting a novel SNP prevalent among people of African descent.
  • The study emphasizes the importance of diverse genetic data in identifying new obesity-related variants, moving us closer to personalized medical interventions for this crisis.
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Stroke is the second leading cause of death and disability worldwide. Stroke prevalence varies by sex and ancestry, possibly due to genetic heterogeneity between subgroups. We performed a genome-wide meta-analysis of 16 biobanks across multiple ancestries to study the genetics of ischemic stroke (60,176 cases, 1,310,725 controls) as part of the Global Biobank Meta-analysis Initiative (GBMI) and further combined the results with previously published MegaStroke.

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  • The study evaluates the effectiveness and shortcomings of polygenic risk scores (PRSs) in predicting various blood pressure (BP) phenotypes among different population groups, focusing on methods like "clumping-and-thresholding" (PRSice2) and LD-based (LDPred2).
  • It utilizes datasets from several biobanks, including MGB Biobank and UK Biobank, to train and validate PRSs based on self-reported race/ethnic backgrounds such as Asian, Black, Hispanic/Latino, and White.
  • Findings indicate that the PRS-CSx method, which combines weighted PRSs from multiple GWAS, provides the most accurate predictions across all racial/ethnic groups, with better effectiveness in females
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Preeclampsia and gestational hypertension are common pregnancy complications associated with adverse maternal and child outcomes. Current tools for prediction, prevention and treatment are limited. Here we tested the association of maternal DNA sequence variants with preeclampsia in 20,064 cases and 703,117 control individuals and with gestational hypertension in 11,027 cases and 412,788 control individuals across discovery and follow-up cohorts using multi-ancestry meta-analysis.

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Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes. To characterise the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study (GWAS) data from 2,535,601 individuals (39.7% non-European ancestry), including 428,452 T2D cases.

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Understanding the DNA methylation patterns in the human genome is a key step to decipher gene regulatory mechanisms and model mutation rate heterogeneity in the human genome. While methylation rates can be measured e.g.

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Biobanks of linked clinical patient histories and biological samples are an efficient strategy to generate large cohorts for modern genetics research. Biobank recruitment varies by factors such as geographic catchment and sampling strategy, which affect biobank demographics and research utility. Here, we describe the Michigan Genomics Initiative (MGI), a single-health-system biobank currently consisting of >91,000 participants recruited primarily during surgical encounters at Michigan Medicine.

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Biobanks facilitate genome-wide association studies (GWASs), which have mapped genomic loci across a range of human diseases and traits. However, most biobanks are primarily composed of individuals of European ancestry. We introduce the Global Biobank Meta-analysis Initiative (GBMI)-a collaborative network of 23 biobanks from 4 continents representing more than 2.

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Population genetics has adapted as technological advances in next-generation sequencing have resulted in an exponential increase of genetic data. A common approach to efficiently analyze genetic variation present in large sequencing data is through the allele frequency spectrum, defined as the distribution of allele frequencies in a sample. While the frequency spectrum serves to summarize patterns of genetic variation, it implicitly assumes mutation types (A→C vs C→T) as interchangeable.

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  • Tobacco and alcohol use contribute significantly to global mortality rates, with heritability playing a key role in these behaviors.
  • This study utilized genetic data from a diverse population of 3.4 million individuals, including 21% non-European ancestry, to identify genetic variants linked to tobacco and alcohol use.
  • Findings showed that while increased genetic diversity improved the identification of genomic loci, polygenic risk scores were less effective across different ancestries, underscoring the need for larger and more diverse genetic datasets for better predictive outcomes.
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For the genomics community, allele frequencies within defined groups (or "strata") are useful across multiple research and clinical contexts. Benefits include allowing researchers to identify populations for replication or "look up" studies, enabling researchers to compare population-specific frequencies to validate findings, and facilitating assessment of variant pathogenicity in clinical contexts. However, there are potential concerns with stratified allele frequencies.

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