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  1. Article ; Online: An evaluation of approaches for rare variant association analyses of binary traits in related samples.

    Chen, Ming-Huei / Pitsillides, Achilleas / Yang, Qiong

    Scientific reports

    2021  Volume 11, Issue 1, Page(s) 3145

    Abstract: Recognizing that family data provide unique advantage of identifying rare risk variants in genetic association studies, many cohorts with related samples have gone through whole genome sequencing in large initiatives such as the NHLBI Trans-Omics for ... ...

    Abstract Recognizing that family data provide unique advantage of identifying rare risk variants in genetic association studies, many cohorts with related samples have gone through whole genome sequencing in large initiatives such as the NHLBI Trans-Omics for Precision Medicine (TOPMed) program. Analyzing rare variants poses challenges for binary traits in that some genotype categories may have few or no observed events, causing bias and inflation in commonly used methods. Several methods have recently been proposed to better handle rare variants while accounting for family relationship, but their performances have not been thoroughly evaluated together. Here we compare several existing approaches including SAIGE but not limited to related samples using simulations based on the Framingham Heart Study samples and genotype data from Illumina HumanExome BeadChip where rare variants are the majority. We found that logistic regression with likelihood ratio test applied to related samples was the only approach that did not have inflated type I error rates in both single variant test (SVT) and gene-based tests, followed by Firth logistic regression that had inflation in its direction insensitive gene-based test at prevalence 0.01 only, applied to either related or unrelated samples, though theoretically logistic regression and Firth logistic regression do not account for relatedness in samples. SAIGE had inflation in SVT at prevalence 0.1 or lower and the inflation was eliminated with a minor allele count filter of 5. As for power, there was no approach that outperformed others consistently among all single variant tests and gene-based tests.
    MeSH term(s) Alleles ; Computer Simulation ; Gene Frequency ; Genome, Human ; Genome-Wide Association Study ; Genotype ; Humans ; Logistic Models ; Longitudinal Studies ; Models, Genetic ; Multifactorial Inheritance ; Polymorphism, Single Nucleotide ; Precision Medicine/methods ; Precision Medicine/statistics & numerical data ; Software
    Language English
    Publishing date 2021-02-04
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-021-82547-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Key variants via the Alzheimer's Disease Sequencing Project whole genome sequence data.

    Wang, Yanbing / Sarnowski, Chloé / Lin, Honghuang / Pitsillides, Achilleas N / Heard-Costa, Nancy L / Choi, Seung Hoan / Wang, Dongyu / Bis, Joshua C / Blue, Elizabeth E / Boerwinkle, Eric / De Jager, Philip L / Fornage, Myriam / Wijsman, Ellen M / Seshadri, Sudha / Dupuis, Josée / Peloso, Gina M / DeStefano, Anita L

    Alzheimer's & dementia : the journal of the Alzheimer's Association

    2024  

    Abstract: Introduction: Genome-wide association studies (GWAS) have identified loci associated with Alzheimer's disease (AD) but did not identify specific causal genes or variants within those loci. Analysis of whole genome sequence (WGS) data, which interrogates ...

    Abstract Introduction: Genome-wide association studies (GWAS) have identified loci associated with Alzheimer's disease (AD) but did not identify specific causal genes or variants within those loci. Analysis of whole genome sequence (WGS) data, which interrogates the entire genome and captures rare variations, may identify causal variants within GWAS loci.
    Methods: We performed single common variant association analysis and rare variant aggregate analyses in the pooled population (N cases = 2184, N controls = 2383) and targeted analyses in subpopulations using WGS data from the Alzheimer's Disease Sequencing Project (ADSP). The analyses were restricted to variants within 100 kb of 83 previously identified GWAS lead variants.
    Results: Seventeen variants were significantly associated with AD within five genomic regions implicating the genes OARD1/NFYA/TREML1, JAZF1, FERMT2, and SLC24A4. KAT8 was implicated by both single variant and rare variant aggregate analyses.
    Discussion: This study demonstrates the utility of leveraging WGS to gain insights into AD loci identified via GWAS.
    Language English
    Publishing date 2024-03-21
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2211627-8
    ISSN 1552-5279 ; 1552-5260
    ISSN (online) 1552-5279
    ISSN 1552-5260
    DOI 10.1002/alz.13705
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Frequency of Variants in Mendelian Alzheimer's Disease Genes within the Alzheimer's Disease Sequencing Project (ADSP).

    Wang, Dongyu / Scalici, Alexandra / Wang, Yanbing / Lin, Honghuang / Pitsillides, Achilleas / Heard-Costa, Nancy / Cruchaga, Carlos / Ziegemeier, Ellen / Bis, Joshua C / Fornage, Myriam / Boerwinkle, Eric / De Jager, Philip L / Wijsman, Ellen / Dupuis, Josée / Renton, Alan E / Seshadri, Sudha / Goate, Alison M / DeStefano, Anita L / Peloso, Gina M

    medRxiv : the preprint server for health sciences

    2024  

    Abstract: Background: Prior studies using the ADSP data examined variants within presenilin-2 ( : Objective: To characterize previously-reported clinically-relevant variants and DM variants in : Methods: We identified rare variants (MAF <1%) previously- ... ...

    Abstract Background: Prior studies using the ADSP data examined variants within presenilin-2 (
    Objective: To characterize previously-reported clinically-relevant variants and DM variants in
    Methods: We identified rare variants (MAF <1%) previously-reported in
    Results: We detected 31 previously-reported clinically-relevant variants with alternate alleles observed within the ADSP: 4 variants in
    Conclusion: A small proportion of individuals in the ADSP are carriers of a previously-reported clinically-relevant variant allele for AD and these participants have significantly earlier age of AD onset compared to non-carriers.
    Language English
    Publishing date 2024-03-29
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.10.24.23297227
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Association analysis of mitochondrial DNA heteroplasmic variants: methods and application.

    Sun, Xianbang / Bulekova, Katia / Yang, Jian / Lai, Meng / Pitsillides, Achilleas N / Liu, Xue / Zhang, Yuankai / Guo, Xiuqing / Yong, Qian / Raffield, Laura M / Rotter, Jerome I / Rich, Stephen S / Abecasis, Goncalo / Carson, April P / Vasan, Ramachandran S / Bis, Joshua C / Psaty, Bruce M / Boerwinkle, Eric / Fitzpatrick, Annette L /
    Satizabal, Claudia L / Arking, Dan E / Ding, Jun / Levy, Daniel / Liu, Chunyu

    medRxiv : the preprint server for health sciences

    2024  

    Abstract: We rigorously assessed a comprehensive association testing framework for heteroplasmy, employing both simulated and real-world data. This framework employed a variant allele fraction (VAF) threshold and harnessed multiple gene-based tests for robust ... ...

    Abstract We rigorously assessed a comprehensive association testing framework for heteroplasmy, employing both simulated and real-world data. This framework employed a variant allele fraction (VAF) threshold and harnessed multiple gene-based tests for robust identification and association testing of heteroplasmy. Our simulation studies demonstrated that gene-based tests maintained an appropriate type I error rate at α=0.001. Notably, when 5% or more heteroplasmic variants within a target region were linked to an outcome, burden-extension tests (including the adaptive burden test, variable threshold burden test, and z-score weighting burden test) outperformed the sequence kernel association test (SKAT) and the original burden test. Applying this framework, we conducted association analyses on whole-blood derived heteroplasmy in 17,507 individuals of African and European ancestries (31% of African Ancestry, mean age of 62, with 58% women) with whole genome sequencing data. We performed both cohort- and ancestry-specific association analyses, followed by meta-analysis on both pooled samples and within each ancestry group. Our results suggest that mtDNA-encoded genes/regions are likely to exhibit varying rates in somatic aging, with the notably strong associations observed between heteroplasmy in the
    Language English
    Publishing date 2024-01-13
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2024.01.12.24301233
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Key variants via Alzheimer's Disease Sequencing Project whole genome sequence data.

    Wang, Yanbing / Sarnowski, Chloé / Lin, Honghuang / Pitsillides, Achilleas N / Heard-Costa, Nancy L / Choi, Seung Hoan / Wang, Dongyu / Bis, Joshua C / Blue, Elizabeth E / Boerwinkle, Eric / De Jager, Philip L / Fornage, Myriam / Wijsman, Ellen M / Seshadri, Sudha / Dupuis, Josée / Peloso, Gina M / DeStefano, Anita L

    medRxiv : the preprint server for health sciences

    2023  

    Abstract: Introduction: Genome-wide association studies (GWAS) have identified loci associated with Alzheimer's disease (AD) but did not identify specific causal genes or variants within those loci. Analysis of whole genome sequence (WGS) data, which interrogates ...

    Abstract Introduction: Genome-wide association studies (GWAS) have identified loci associated with Alzheimer's disease (AD) but did not identify specific causal genes or variants within those loci. Analysis of whole genome sequence (WGS) data, which interrogates the entire genome and captures rare variations, may identify causal variants within GWAS loci.
    Methods: We performed single common variant association analysis and rare variant aggregate analyses in the pooled population (N cases=2,184, N controls=2,383) and targeted analyses in sub-populations using WGS data from the Alzheimer's Disease Sequencing Project (ADSP). The analyses were restricted to variants within 100 kb of 83 previously identified GWAS lead variants.
    Results: Seventeen variants were significantly associated with AD within five genomic regions implicating the genes OARD1/NFYA/TREML1, JAZF1, FERMT2, and SLC24A4. KAT8 was implicated by both single variant and rare variant aggregate analyses.
    Discussion: This study demonstrates the utility of leveraging WGS to gain insights into AD loci identified via GWAS.
    Language English
    Publishing date 2023-08-29
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.08.28.23294631
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Elucidating the genetic architecture of DNA methylation to identify promising molecular mechanisms of disease.

    Ma, Jiantao / Joehanes, Roby / Liu, Chunyu / Keshawarz, Amena / Hwang, Shih-Jen / Bui, Helena / Tejada, Brandon / Sooda, Meera / Munson, Peter J / Demirkale, Cumhur Y / Courchesne, Paul / Heard-Costa, Nancy L / Pitsillides, Achilleas N / Feolo, Mike / Sharopova, Nataliya / Vasan, Ramachandran S / Huan, Tianxiao / Levy, Daniel

    Scientific reports

    2022  Volume 12, Issue 1, Page(s) 19564

    Abstract: DNA methylation commonly occurs at cytosine-phosphate-guanine sites (CpGs) that can serve as biomarkers for many diseases. We analyzed whole genome sequencing data to identify DNA methylation quantitative trait loci (mQTLs) in 4126 Framingham Heart Study ...

    Abstract DNA methylation commonly occurs at cytosine-phosphate-guanine sites (CpGs) that can serve as biomarkers for many diseases. We analyzed whole genome sequencing data to identify DNA methylation quantitative trait loci (mQTLs) in 4126 Framingham Heart Study participants. Our mQTL mapping identified 94,362,817 cis-mQTLvariant-CpG pairs (for 210,156 unique autosomal CpGs) at P < 1e-7 and 33,572,145 trans-mQTL variant-CpG pairs (for 213,606 unique autosomal CpGs) at P < 1e-14. Using cis-mQTL variants for 1258 CpGs associated with seven cardiovascular disease (CVD) risk factors, we found 104 unique CpGs that colocalized with at least one CVD trait. For example, cg11554650 (PPP1R18) colocalized with type 2 diabetes, and was driven by a single nucleotide polymorphism (rs2516396). We performed Mendelian randomization (MR) analysis and demonstrated 58 putatively causal relations of CVD risk factor-associated CpGs to one or more risk factors (e.g., cg05337441 [APOB] with LDL; MR P = 1.2e-99, and 17 causal associations with coronary artery disease (e.g. cg08129017 [SREBF1] with coronary artery disease; MR P = 5e-13). We also showed that three CpGs, e.g., cg14893161 (PM20D1), are putatively causally associated with COVID-19 severity. To assist in future analyses of the role of DNA methylation in disease pathogenesis, we have posted a comprehensive summary data set in the National Heart, Lung, and Blood Institute's BioData Catalyst.
    MeSH term(s) Humans ; DNA Methylation ; Diabetes Mellitus, Type 2/genetics ; Coronary Artery Disease/genetics ; COVID-19 ; Quantitative Trait Loci ; Polymorphism, Single Nucleotide ; Cytosine ; CpG Islands/genetics ; Genome-Wide Association Study
    Chemical Substances Cytosine (8J337D1HZY)
    Language English
    Publishing date 2022-11-15
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Intramural ; Research Support, N.I.H., Extramural
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-022-24100-0
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  7. Article: Association of genetic variations and gene expression in a family-based study.

    Pitsillides, Achilleas N / Choi, Seung-Hoan / Hogan, John D / Hong, Jaeyoung / Lin, Honghuang

    BMC proceedings

    2016  Volume 10, Issue Suppl 7, Page(s) 109–112

    Abstract: Background: Expression quantitative trait locus (eQTL) maps are considered a valuable resource in studying complex diseases. The availability of gene expression data from the Genetic Analysis Workshop 19 (GAW19) provides a great opportunity to ... ...

    Abstract Background: Expression quantitative trait locus (eQTL) maps are considered a valuable resource in studying complex diseases. The availability of gene expression data from the Genetic Analysis Workshop 19 (GAW19) provides a great opportunity to investigate the association of gene expression with genetic variants in blood.
    Methods: A total of 267 samples with gene expression and whole genome sequencing data were employed in this study. We used linear mixed models with genetic random effects along with a permutation procedure to create an eQTL map. The eQTL map was further tested in terms of functional implication, including the enrichment in disease-related variants and in regulatory regions.
    Results: We identified 22,869 significant eQTLs from the GAW19 data set. These eQTLs were highly enriched with genetic loci associated with blood pressure and DNase hypersensitive regions. In addition, the majority of genes associated with eQTLs showed moderate to high heritability (
    Conclusions: We successfully created an eQTL map from the GAW19 data set. Our study indicated that the eQTLs were enriched within regulatory regions, and tended to have relatively high heritability.
    Language English
    Publishing date 2016-10-18
    Publishing country England
    Document type Journal Article
    ZDB-ID 2411867-9
    ISSN 1753-6561
    ISSN 1753-6561
    DOI 10.1186/s12919-016-0014-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: An efficient analytic approach in genome-wide identification of methylation quantitative trait loci response to fenofibrate treatment.

    Cox, Jiayi Wu / Patel, Devanshi / Chung, Jaeyoon / Zhu, Congcong / Lent, Samantha / Fisher, Virginia / Pitsillides, Achilleas / Farrer, Lindsay / Zhang, Xiaoling

    BMC proceedings

    2018  Volume 12, Issue Suppl 9, Page(s) 44

    Abstract: Background: The study of DNA methylation quantitative trait loci (meQTLs) helps dissect regulatory mechanisms underlying genetic associations of human diseases. In this study, we conducted the first genome-wide examination of genetic drivers of ... ...

    Abstract Background: The study of DNA methylation quantitative trait loci (meQTLs) helps dissect regulatory mechanisms underlying genetic associations of human diseases. In this study, we conducted the first genome-wide examination of genetic drivers of methylation variation in response to a triglyceride-lowering treatment with fenofibrate (response-meQTL) by using an efficient analytic approach.
    Methods: Subjects (
    Results: We identified 1087 SNPs as
    Conclusions: By using a novel analytic approach, we efficiently identified thousands of
    Language English
    Publishing date 2018-09-17
    Publishing country England
    Document type Journal Article
    ZDB-ID 2411867-9
    ISSN 1753-6561
    ISSN 1753-6561
    DOI 10.1186/s12919-018-0152-7
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Hypoglycemia risk and glucose variability indices derived from routine self-monitoring of blood glucose are related to laboratory measures of insulin sensitivity and epinephrine counterregulation.

    Pitsillides, Achilleas N / Anderson, Stacey M / Kovatchev, Boris

    Diabetes technology & therapeutics

    2011  Volume 13, Issue 1, Page(s) 11–17

    Abstract: Background: the widely held assumptions that in type 1 diabetes glucose variability may correlate with insulin sensitivity and impaired epinephrine counterregulation have not been studied directly. Here we investigate possible relationships between ... ...

    Abstract Background: the widely held assumptions that in type 1 diabetes glucose variability may correlate with insulin sensitivity and impaired epinephrine counterregulation have not been studied directly. Here we investigate possible relationships between outpatient measures of glucose variability and risk for hypoglycemia with physiological characteristics: insulin sensitivity and hypoglycemia counterregulation.
    Methods: thirty-four subjects with type 1 diabetes (14 women, 20 men; 37 ± 2.1 years old; glycosylated hemoglobin [HbA1c], 7.6  ±  0.21%) performed self-monitoring of blood glucose (SMBG) for a month, followed by an inpatient hyperinsulinemic euglycemic and hypoglycemic clamp. SMBG field data were used to calculate measures of glucose variability and risk of hypoglycemia, while the clamp procedure was used to evaluate insulin sensitivity and epinephrine response during induced hypoglycemia. Spearman partial correlations adjusted for age, duration of diabetes, body mass index, gender, and HbA1c were used to assess the relationship between the field indices of glucose variability and the physiological characteristics of diabetes.
    Results: two glucose variability measures correlated positively (P < 0.01) with insulin sensitivity: the Average Daily Risk Range (ADRR) (ρ = 0.5) and the Glycemic Lability Index (ρ = 0.48). The Low Blood Glucose Index, a measure of the risk for hypoglycemia, and the ADRR correlated negatively with maximum epinephrine response during hypoglycemia: ρ = -0.46, P < 0.01 and ρ = -0.4, P = 0.03, respectively.
    Conclusions: higher insulin sensitivity and lower epinephrine response during hypoglycemia are related to increased glucose variability (as quantified by the ADRR), irrespective of HbA1c and other patient characteristics. Lower epinephrine relates to risk for hypoglycemia as well.
    MeSH term(s) Adolescent ; Adult ; Blood Glucose/metabolism ; Blood Glucose Self-Monitoring/methods ; Diabetes Mellitus, Type 1/blood ; Epinephrine/blood ; Female ; Glucose Clamp Technique ; Humans ; Hypoglycemia/blood ; Insulin Resistance/physiology ; Male ; Middle Aged ; Statistics, Nonparametric ; Young Adult
    Chemical Substances Blood Glucose ; Epinephrine (YKH834O4BH)
    Language English
    Publishing date 2011-01-20
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 1452816-2
    ISSN 1557-8593 ; 1520-9156
    ISSN (online) 1557-8593
    ISSN 1520-9156
    DOI 10.1089/dia.2010.0103
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Whole genome DNA and RNA sequencing of whole blood elucidates the genetic architecture of gene expression underlying a wide range of diseases.

    Liu, Chunyu / Joehanes, Roby / Ma, Jiantao / Wang, Yuxuan / Sun, Xianbang / Keshawarz, Amena / Sooda, Meera / Huan, Tianxiao / Hwang, Shih-Jen / Bui, Helena / Tejada, Brandon / Munson, Peter J / Demirkale, Cumhur Y / Heard-Costa, Nancy L / Pitsillides, Achilleas N / Peloso, Gina M / Feolo, Michael / Sharopova, Nataliya / Vasan, Ramachandran S /
    Levy, Daniel

    Scientific reports

    2022  Volume 12, Issue 1, Page(s) 20167

    Abstract: To create a scientific resource of expression quantitative trail loci (eQTL), we conducted a genome-wide association study (GWAS) using genotypes obtained from whole genome sequencing (WGS) of DNA and gene expression levels from RNA sequencing (RNA-seq) ... ...

    Abstract To create a scientific resource of expression quantitative trail loci (eQTL), we conducted a genome-wide association study (GWAS) using genotypes obtained from whole genome sequencing (WGS) of DNA and gene expression levels from RNA sequencing (RNA-seq) of whole blood in 2622 participants in Framingham Heart Study. We identified 6,778,286 cis-eQTL variant-gene transcript (eGene) pairs at p < 5 × 10
    MeSH term(s) Humans ; DNA ; Gene Expression ; Genetic Predisposition to Disease ; Genome-Wide Association Study ; Quantitative Trait Loci/genetics ; Sequence Analysis, RNA
    Chemical Substances DNA (9007-49-2)
    Language English
    Publishing date 2022-11-23
    Publishing country England
    Document type Journal Article
    ZDB-ID 2615211-3
    ISSN 2045-2322 ; 2045-2322
    ISSN (online) 2045-2322
    ISSN 2045-2322
    DOI 10.1038/s41598-022-24611-w
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