Browsing by Subject "Multifactorial Inheritance"

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    Polygenic mediation analysis of Alzheimer's disease implicated intermediate amyloid imaging phenotypes
    (American Medical Informatics Association, 2021-01-25) Eng, Yingxuan; Yao, Xiaohui; Liu, Kefei; Risacher, Shannon L.; Saykin, Andrew J.; Long, Qi; Zhao, Yize; Shen, Li; Radiology and Imaging Sciences, School of Medicine
    Mediation models have been employed in the study of brain disorders to detect the underlying mechanisms between genetic variants and diagnostic outcomes implicitly mediated by intermediate imaging biomarkers. However, the statistical power is influenced by the modest effects of individual genetic variants on both diagnostic and imaging phenotypes and the limited sample sizes ofimaging genetic cohorts. In this study, we propose a polygenic mediation analysis that comprises a polygenic risk score (PRS) to aggregate genetic effects ofa set ofcandidate variants and then explore the implicit effect ofimaging phenotypes between the PRS and disease status. We applied our proposed method to an amyloid imaging genetic study of Alzheimer's disease (AD), identified multiple imaging mediators linking PRS with AD, and further demonstrated the promise of the PRS on mediator detection over individual variants alone.
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    Polygenic Scores for Major Depressive Disorder and Risk of Alcohol Dependence
    (American Medical Association, 2017-11-01) Andersen, Allan M.; Pietrzak, Robert H.; Kranzler, Henry R.; Ma, Li; Zhou, Hang; Liu, Xiaoming; Kramer, John; Kuperman, Samuel; Edenberg, Howard J.; Nurnberger, John I., Jr.; Rice, John P.; Tischfield, Jay A.; Goate, Alison; Foroud, Tatiana M.; Meyers, Jacquelyn L.; Porjesz, Bernice; Dick, Danielle M.; Hesselbrock, Victor; Boerwinkle, Eric; Southwick, Steven M.; Krystal, John H.; Weissman, Myrna M.; Levinson, Douglas F.; Potash, James B.; Gelernter, Joel; Han, Shizhong; Biochemistry and Molecular Biology, School of Medicine
    Importance: Major depressive disorder (MDD) and alcohol dependence (AD) are heritable disorders with significant public health burdens, and they are frequently comorbid. Common genetic factors that influence the co-occurrence of MDD and AD have been sought in family, twin, and adoption studies, and results to date have been promising but inconclusive. Objective: To examine whether AD and MDD overlap genetically, using a polygenic score approach. Design, Settings, and Participants: Association analyses were conducted between MDD polygenic risk score (PRS) and AD case-control status in European ancestry samples from 4 independent genome-wide association study (GWAS) data sets: the Collaborative Study on the Genetics of Alcoholism (COGA); the Study of Addiction, Genetics, and Environment (SAGE); the Yale-Penn genetic study of substance dependence; and the National Health and Resilience in Veterans Study (NHRVS). Results from a meta-analysis of MDD (9240 patients with MDD and 9519 controls) from the Psychiatric Genomics Consortium were applied to calculate PRS at thresholds from P < .05 to P ≤ .99 in each AD GWAS data set. Main Outcomes and Measures: Association between MDD PRS and AD. Results: Participants analyzed included 788 cases (548 [69.5%] men; mean [SD] age, 38.2 [10.8] years) and 522 controls (151 [28.9.%] men; age [SD], 43.9 [11.6] years) from COGA; 631 cases (333 [52.8%] men; age [SD], 35.0 [7.7] years) and 756 controls (260 [34.4%] male; age [SD] 36.1 [7.7] years) from SAGE; 2135 cases (1375 [64.4%] men; age [SD], 39.4 [11.5] years) and 350 controls (126 [36.0%] men; age [SD], 43.5 [13.9] years) from Yale-Penn; and 317 cases (295 [93.1%] men; age [SD], 59.1 [13.1] years) and 1719 controls (1545 [89.9%] men; age [SD], 64.5 [13.3] years) from NHRVS. Higher MDD PRS was associated with a significantly increased risk of AD in all samples (COGA: best P = 1.7 × 10-6, R2 = 0.026; SAGE: best P = .001, R2 = 0.01; Yale-Penn: best P = .035, R2 = 0.0018; and NHRVS: best P = .004, R2 = 0.0074), with stronger evidence for association after meta-analysis of the 4 samples (best P = 3.3 × 10-9). In analyses adjusted for MDD status in 3 AD GWAS data sets, similar patterns of association were observed (COGA: best P = 7.6 × 10-6, R2 = 0.023; Yale-Penn: best P = .08, R2 = 0.0013; and NHRVS: best P = .006, R2 = 0.0072). After recalculating MDD PRS using MDD GWAS data sets without comorbid MDD-AD cases, significant evidence was observed for an association between the MDD PRS and AD in the meta-analysis of 3 GWAS AD samples without MDD cases (best P = .007). Conclusions and Relevance: These results suggest that shared genetic susceptibility contributes modestly to MDD and AD comorbidity. Individuals with elevated polygenic risk for MDD may also be at risk for AD.