Medicine and Health Sciences Commons^™

Unraveling Dilated Cardiomyopathy Linked To An Enigmatic Mybpc3 Variant, Khiem D. Ngo, Carlos Alejos, Jennifer Rojas, Sobia Memon, James Stone

Research Colloquium

Background: Non-ischemic cardiomyopathy (NICM), can arise from various causes, including hemodynamic pathology, infections, immunologic abnormalities, toxic injuries, and genetic factors. Determining the prevalence of NICM is challenging due to varying definitions and diagnostic criteria, selection bias, and geographic variation. MYBPC3 is the primary gene known to cause restrictive cardiomyopathy, dilated cardiomyopathy, and left ventricular non-compaction. This gene encodes cMyBP-C, a structural protein of the heart muscle that interacts with actin, myosin, and titin to maintain sarcomeric integrity. While loss-of-function mutations are common, MYBPC3 missense variants of uncertain significance (VUS) are also prevalent. Individuals with MYBPC3 missense VUS predicted to disrupt …

The Genetic Determinants Of Recurrent Somatic Mutations In 43,693 Blood Genomes, Joshua S. Weinstock, Cecelia A. Laurie, Jai G. Broome, Kent D. Taylor, Xiuqing Guo, Alan R. Shuldiner, Jeffrey R. O'Connell, Ravi Duggirala, Joanne E. Curran, John Blangero

School of Medicine Publications and Presentations

Nononcogenic somatic mutations are thought to be uncommon and inconsequential. To test this, we analyzed 43,693 National Heart, Lung and Blood Institute Trans-Omics for Precision Medicine blood whole genomes from 37 cohorts and identified 7131 non-missense somatic mutations that are recurrently mutated in at least 50 individuals. These recurrent non-missense somatic mutations (RNMSMs) are not clearly explained by other clonal phenomena such as clonal hematopoiesis. RNMSM prevalence increased with age, with an average 50-year-old having 27 RNMSMs. Inherited germline variation associated with RNMSM acquisition. These variants were found in genes involved in adaptive immune function, proinflammatory cytokine production, and lymphoid …

Non-Alcoholic Fatty Liver Disease And Depression: Evidence For Genotype × Environment Interaction In Mexican Americans, Eron G. Manusov, Vincent P. Diego, Khalid Sheikh, Sandra Laston, John Blangero, Sarah Williams-Blangero

School of Medicine Publications and Presentations

This study examines the impact of G × E interaction effects on non-alcoholic fatty liver disease (NAFLD) among Mexican Americans in the Rio Grande Valley (RGV) of South Texas. We examined potential G × E interaction using variance components models and likelihood-based statistical inference in the phenotypic expression of NAFLD, including hepatic steatosis and hepatic fibrosis (identified using vibration controlled transient elastography and controlled attenuation parameter measured by the FibroScan Device). We screened for depression using the Beck Depression Inventory-II (BDI-II). We identified significant G × E interactions for hepatic fibrosis × BDI-II. These findings provide evidence that genetic factors …

Identification Of Healthspan-Promoting Genes In Caenorhabditis Elegans Based On A Human Gwas Study, Nadine Saul, Ineke Dhondt, Mikko Kuokkanen, Markus Perola, Clara Verschuuren, Brecht Wouters, Henrik Von Chrzanowski, Winnok H. De Vos, Liesbet Temmerman, Walter Luyten

School of Medicine Publications and Presentations

To find drivers of healthy ageing, a genome-wide association study (GWAS) was performed in healthy and unhealthy older individuals. Healthy individuals were defined as free from cardiovascular disease, stroke, heart failure, major adverse cardiovascular event, diabetes, dementia, cancer, chronic obstructive pulmonary disease (COPD), asthma, rheumatism, Crohn’s disease, malabsorption or kidney disease. Six single nucleotide polymorphisms (SNPs) with unknown function associated with ten human genes were identified as candidate healthspan markers. Thirteen homologous or closely related genes were selected in the model organism C. elegans for evaluating healthspan after targeted RNAi-mediated knockdown using pathogen resistance, muscle integrity, chemotaxis index and the …

Mendelian Randomization Supports Bidirectional Causality Between Telomere Length And Clonal Hematopoiesis Of Indeterminate Potential, Tetsushi Nakao, Alexander G. Bick, Margaret A. Taub, Seyedeh M. Zekavat, Md M. Uddin, Abhishek Niroula, Juan M. Peralta, Joanne E. Curran, John Blangero

School of Medicine Publications and Presentations

Human genetic studies support an inverse causal relationship between leukocyte telomere length (LTL) and coronary artery disease (CAD), but directionally mixed effects for LTL and diverse malignancies. Clonal hematopoiesis of indeterminate potential (CHIP), characterized by expansion of hematopoietic cells bearing leukemogenic mutations, predisposes both hematologic malignancy and CAD. TERT (which encodes telomerase reverse transcriptase) is the most significantly associated germline locus for CHIP in genome-wide association studies. Here, we investigated the relationship between CHIP, LTL, and CAD in the Trans-Omics for Precision Medicine (TOPMed) program (n = 63,302) and UK Biobank (n = 47,080). Bidirectional Mendelian randomization studies …

Whole Genome Sequence Analysis Of Platelet Traits In The Nhlbi Trans-Omics For Precision Medicine Initiative, Amarise Little, Yao Hu, Quan Sun, Deepti Jain, Jai G. Broome, Ming-Huei Chen, Florian Thibord, Caitlin Mchugh, John Blangero, Joanne E. Curran

School of Medicine Publications and Presentations

Platelets play a key role in thrombosis and hemostasis. Platelet count (PLT) and mean platelet volume (MPV) are highly heritable quantitative traits, with hundreds of genetic signals previously identified, mostly in European ancestry populations. We here utilize whole genome sequencing from NHLBI's Trans-Omics for Precision Medicine Initiative (TOPMed) in a large multi-ethnic sample to further explore common and rare variation contributing to PLT (n = 61 200) and MPV (n = 23 485). We identified and replicated secondary signals at MPL (rs532784633) and PECAM1 (rs73345162), both more common in African ancestry populations. We also observed rare variation in Mendelian platelet …

Whole Genome Sequence Data From Captive Baboons Implicate Rbfox1 In Epileptic Seizure Risk, Mark Z. Kos, Melanie A. Carless, Lucy Blondell, M. Michelle Leland, Koyle D. Knape, Harald Hh Goring, Charles A. Szabo

School of Medicine Publications and Presentations

In this study, we investigate the genetic determinants that underlie epilepsy in a captive baboon pedigree and evaluate the potential suitability of this non-human primate model for understanding the genetic etiology of human epilepsy. Archived whole-genome sequence data were analyzed using both a candidate gene approach that targeted variants in baboon homologs of 19 genes (n = 20,881 SNPs) previously implicated in genetic generalized epilepsy (GGE) and a more agnostic approach that examined protein-altering mutations genome-wide as assessed by snpEff (n = 36,169). Measured genotype association tests for baboon cases of epileptic seizure were performed using SOLAR, as …

Inherited Causes Of Clonal Haematopoiesis In 97,691 Whole Genomes, Alexander G. Bick, Joshua S. Weinstock, Satish K. Nandakumar, Charles P. Fulco, Erik L. Bao, Seyedeh M. Zekavat, Mindy D. Szeto, Juan M. Peralta, Joanne E. Curran, John Blangero

School of Medicine Publications and Presentations

Age is the dominant risk factor for most chronic human diseases, but the mechanisms through which ageing confers this risk are largely unknown1. The age-related acquisition of somatic mutations that lead to clonal expansion in regenerating haematopoietic stem cell populations has recently been associated with both haematological cancer2,3,4 and coronary heart disease5—this phenomenon is termed clonal haematopoiesis of indeterminate potential (CHIP)6. Simultaneous analyses of germline and somatic whole-genome sequences provide the opportunity to identify root causes of CHIP. Here we analyse high-coverage whole-genome sequences from 97,691 participants of diverse …

Crispr Cas9 Genome Editing In Human Cell Lines With Donor Vector Made By Gibson Assembly, Nirakar Sahoo, Victoria Cuello, Shreya Udawant, Carl Litif, Julie A. Mustard, Megan Keniry

Biology Faculty Publications and Presentations

CRISPR Cas9 genome editing allows researchers to modify genesin a multitude of ways including to obtain deletions, epitope-tagged loci, and knock-in mutations. Within six years of its initial application, CRISPR Cas9 genome editing has become widely employed, but disadvantages to this method, such as low modification efficiencies and off-target effects,need careful consideration. Obtaining custom donor vectors can also be expensive and time consuming. This chapter details strategies to overcome barriers to CRISPR Cas9 genome editing as well as recent developments in employing this technique.

Fine Mapping And Identification Of Serum Urate Loci In American Indians: The Strong Heart Family Study, Geetha Chittoor, Karin Haack, Poojitha Balakrishnan, Christopher Bizon, Sandra Laston, Lyle G. Best, Jean W. Maccluer, Kari E. North, Jason G. Umans

School of Medicine Publications and Presentations

While studies have reported genetic loci affecting serum urate (SU) concentrations, few studies have been conducted in minority populations. Our objective for this study was to identify genetic loci regulating SU in a multigenerational family-based cohort of American Indians, the Strong Heart Family Study (SHFS). We genotyped 162,718 single nucleotide polymorphisms (SNPs) in 2000 SHFS participants using an Illumina MetaboChip array. A genome-wide association analysis of SU was conducted using measured genotype analysis approach accounting for kinships in SOLAR, and meta-analysis in METAL. Our results showed strong association of SU with rs4481233, rs9998811, rs7696092 and rs13145758 (minor allele frequency (MAF) …

Genetic And Environmental (Physical Fitness And Sedentary Activity) Interaction Effects On Cardiometabolic Risk Factors In Mexican American Children And Adolescents, Rector Arya, Vidya S. Farook, Sharon P. Fowler, Sobha Puppala, Geetha Chittoor, Roy G. Resendez, Srinivas Mummidi, Jairam Vanamala, Laura Almasy, Joanne E. Curran, Donna M. Lehman, Christopher P. Jenkinson, Jane L. Lynch, Ralph A. Defronzo, John Blangero, Ravindranath Duggirala, Vincent P. Diego

School of Medicine Publications and Presentations

Knowledge on genetic and environmental (G × E) interaction effects on cardiometabolic risk factors (CMRFs) in children is limited. The purpose of this study was to examine the impact of G × E interaction effects on CMRFs in Mexican American (MA) children (n = 617, ages 6–17 years). The environments examined were sedentary activity (SA), assessed by recalls from “yesterday” (SAy) and “usually” (SAu) and physical fitness (PF) assessed by Harvard PF scores (HPFS). CMRF data included body mass index (BMI), waist circumference (WC), fat mass (FM), fasting insulin (FI), homeostasis model of assessment—insulin resistance (HOMA‐IR), high‐density lipoprotein cholesterol …

Deep Coverage Whole Genome Sequences And Plasma Lipoprotein(A) In Individuals Of European And African Ancestries, Seyedeh M. Zekavat, Sanni Ruotsalainen, Robert E. Handsaker, Maris Alver, Jonathan Bloom, Timothy Poterba, Laura Almasy, John Blangero, Joanne E. Curran, Ravindranath Duggirala, Juan M. Peralta, Harald H. H. Goring

School of Medicine Publications and Presentations

Lipoprotein(a), Lp(a), is a modified low-density lipoprotein particle that contains apolipoprotein(a), encoded by LPA, and is a highly heritable, causal risk factor for cardiovascular diseases that varies in concentrations across ancestries. Here, we use deep-coverage whole genome sequencing in 8392 individuals of European and African ancestry to discover and interpret both single-nucleotide variants and copy number (CN) variation associated with Lp(a). We observe that genetic determinants between Europeans and Africans have several unique determinants. The common variant rs12740374 associated with Lp(a) cholesterol is an eQTL for SORT1 and independent of LDL cholesterol. Observed associations of aggregates of rare non-coding …

Genetic Variation And Gene Expression Across Multiple Tissues And Developmental Stages In A Non-Human Primate, Anna J. Jasinska, Ivette Zelaya, Susan K. Service, Christine B. Peterson, Rita M. Cantor, Oi-Wa Choi, Joseph Deyoung, Eleazar Eskin, Lynn A. Fairbanks, John Blangero, Thomas D. Dyer

School of Medicine Publications and Presentations

By analyzing multitissue gene expression and genome-wide genetic variation data in samples from a vervet monkey pedigree, we generated a transcriptome resource and produced the first catalog of expression quantitative trait loci (eQTLs) in a nonhuman primate model. This catalog contains more genome-wide significant eQTLs per sample than comparable human resources and identifies sex- and age-related expression patterns. Findings include a master regulatory locus that likely has a role in immune function and a locus regulating hippocampal long noncoding RNAs (lncRNAs), whose expression correlates with hippocampal volume. This resource will facilitate genetic investigation of quantitative traits, including brain and behavioral …

Identity-By-Descent Mapping Identifies Major Locus For Serum Triglycerides In Amerindians Largely Explained By An Apoc3 Founder Mutation, Wen-Chi Hsueh, Anup K. Nair, Sayuko Kobes, Peng Chen, Harald H. H. Goring, Toni I. Pollin, Alka Malhotra, William C. Knowler, Leslie J. Baier, Robert L. Hanson

School of Medicine Publications and Presentations

Background—Identity-by-descent (IBD) mapping using empirical estimates of IBD allele sharing may be useful for studies of complex traits in founder populations, where hidden relationships may augment the inherent genetic information that can be used for localization.

Methods and Results—Through IBD mapping, using ~400,000 SNPs, of serum lipid profiles we identified a major linkage signal for triglycerides (TG) in 1,007 Pima Indians (LOD=9.23, p=3.5×10−11 on chromosome 11q). In subsequent fine-mapping and replication association studies in ~7,500 Amerindians, we determined that this signal reflects effects of a loss-of-function Ala43Thr substitution in APOC3 (rs147210663) and 3 established functional SNPs in APOA5. …

Benchmarking Relatedness Inference Methods With Genome-Wide Data From Thousands Of Relatives, Monica D. Ramstetter, Thomas D. Dyer, Donna M. Lehman, Joanne E. Curran, Ravindranath Duggirala, John Blangero, Jason G. Mezey, Amy L. Williams

School of Medicine Publications and Presentations

Inferring relatedness from genomic data is an essential component of genetic association studies, population genetics, forensics, and genealogy. While numerous methods exist for inferring relatedness, thorough evaluation of these approaches in real data has been lacking. Here, we report an assessment of 12 state-of-the-art pairwise relatedness inference methods using a data set with 2485 individuals contained in several large pedigrees that span up to six generations. We find that all methods have high accuracy (92–99%) when detecting first- and second-degree relationships, but their accuracy dwindles to76% of relative pairs. Overall, the most accurate methods are Estimation of Recent Shared Ancestry …

Epigenetic Age Acceleration Assessed With Human White-Matter Images, Karen Hodgson, Melanie A. Carless, Hemant Kulkarni, Joanne E. Curran, Emma Sprooten, Emma E. Knowles, Samuel R. Mathias, Harald H. H. Goring, Nailin Yao, Rene L. Olvera, Laura Almasy, Ravindranath Duggirala, John Blangero, David C. Glahn

School of Medicine Publications and Presentations

The accurate estimation of age using methylation data has proved a useful and heritable biomarker, with acceleration in epigenetic age predicting a number of age-related phenotypes. Measures of white matter integrity in the brain are also heritable and highly sensitive to both normal and pathological aging processes across adulthood. We consider the phenotypic and genetic interrelationships between epigenetic age acceleration and white matter integrity in humans. Our goal was to investigate processes that underlie interindividual variability in age-related changes in the brain. Using blood taken from a Mexican-American extended pedigree sample (n = 628; age = 23.28-93.11 years), epigenetic …

Multiethnic Genome-Wide Meta-Analysis Of Ectopic Fat Depots Identifies Loci Associated With Adipocyte Development And Differentiation, Audrey Y. Chu, Xuan Deng, Virginia A. Fisher, Alexander Drong, Yang Zhang, Mary F. Feitosa, Ching-Ti Liu, Olivia Weeks, Audrey C. Choh, Qing Duan, Thomas D. Dyer

School of Medicine Publications and Presentations

Variation in body fat distribution contributes to the metabolic sequelae of obesity. The genetic determinants of body fat distribution are poorly understood. The goal of this study was to gain new insights into the underlying genetics of body fat distribution by conducting sample-size weighted fixed-effects genome-wide association meta-analyses in up to 9,594 women and 8,738 men for six ectopic fat traits in European, African, Hispanic, and Chinese ancestry populations, with and without sex stratification. In total, 7 new loci were identified in association with ectopic fat traits (ATXN1, UBE2E2, EBF1, RREB1, GSDMB, GRAMD3 and ENSA; PATXN1 and UBE2E2 …

Lack Of Association Between Slc30a8 Variants And Type 2 Diabetes In Mexican American Families, Hemant Kulkarni, Manju Mamtani, Juan M. Peralta, Vincent P. Diego, Thomas D. Dyer, Harald H. H. Goring, Laura Almasy, Sarah Williams-Blangero, Michael C. Mahaney, Ravindranath Duggirala, Joanne E. Curran, John Blangero

School of Medicine Publications and Presentations

SLC30A8 encodes zinc transporter 8 which is involved in packaging and release of insulin. Evidence for the association of SLC30A8 variants with type 2 diabetes (T2D) is inconclusive. We interrogated single nucleotide polymorphisms (SNPs) around SLC30A8 for association with T2D in high-risk, pedigreed individuals from extended Mexican American families. This study of 118 SNPs within 50 kb of the SLC30A8 locus tested the association with eight T2D-related traits at four levels: (i) each SNP using measured genotype approach (MGA); (ii) interaction of SNPs with age and sex; (iii) combinations of SNPs using Bayesian Quantitative Trait Nucleotide (BQTN) analyses; and (iv) …