John Lynn Jefferies

Dr. John Lynn Jefferies

1. Department of Internal Medicine and Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 July 2011 in Genome Biology
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Journal Article
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MBMatthew N Bainbridge
Matthew N Bainbridge
MWMin Wang
Min Wang
YWYuanqing Wu
Yuanqing Wu
INIrene Newsham
Irene Newsham
DMDonna M Muzny
Donna M Muzny
RGRichard A Gibbs
Richard A Gibbs
Background: Enrichment of loci by DNA hybridization-capture, followed by high-throughput sequencing, is an important tool in modern genetics. Currently, the most common targets for enrichment are the protein coding exons represented by the consensus coding DNA sequence (CCDS). The CCDS, however, excludes many actual or computationally predicted coding exons present in other databases, such as RefSeq and Vega, and non-coding functional elements such as untranslated and regulatory regions. The number of variants per base pair (variant density) and our ability to interrogate regions outside of the CCDS regions is consequently less well understood. Results: We examine capture sequence data from outside of the CCDS regions and find that extremes of GC content that are present in different subregions of the genome can reduce the local capture sequence coverage to less than 50% relative to the CCDS. This effect is due to biases inherent in both the Illumina and SOLiD sequencing platforms that are exacerbated by the capture process. Interestingly, for two subregion types, microRNA and predicted exons, the capture process yields higher than expected coverage when compared to whole genome sequencing. Lastly, we examine the variation present in non-CCDS regions and find that predicted exons, as well as exonic regions specific to RefSeq and Vega, show much higher variant densities than the CCDS. Conclusions: We show that regions outside of the CCDS perform less efficiently in capture sequence experiments. Further, we show that the variant density in computationally predicted exons is more than 2.5-times higher than that observed in the CCDS.

1 November 2015 in Journal of Cardiac Failure
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Journal Article
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John Lynn JefferiesJohn Lynn Jefferies
John Lynn Jefferies
JWJames D. Wilkinson
James D. Wilkinson
LSLynn A. Sleeper
Lynn A. Sleeper
SCSteven D. Colan
Steven D. Colan
MLMinmin Lu
Minmin Lu
JTJeffrey A. Towbin
Jeffrey A. Towbin

1 January 2013 in Journal of Cardiovascular Magnetic Resonance
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Journal Article
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KHKan N Hor
Kan N Hor
MTMichael D Taylor
Michael D Taylor
HAHussein R Al-Khalidi
Hussein R Al-Khalidi
LCLinda H Cripe
Linda H Cripe
SRSubha V Raman
Subha V Raman
WMWojciech Mazur
Wojciech Mazur
Duchenne muscular dystrophy (DMD), an X-linked disorder affects approximately 1 in 5000 males, is universally associated with heart disease. We previously identified myocardial disease by late gadolinium enhancement (LGE) in DMD subjects at various stages of disease, but the true prevalence is unclear. Cardiovascular magnetic resonance (CMR) is well established for both assessment of ventricular function and myocardial fibrosis by LGE. We sought to establish i) prevalence and distribution of LGE in a large DMD population and ii) relationship among LGE, age, LVEF by CMR and current living status.

10 July 2013 in American Journal of Medical Genetics Part C: Seminars in Medical Genetics
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John Lynn JefferiesJohn Lynn Jefferies
John Lynn Jefferies
Barth syndrome (BTHS) is an X‐linked recessive disorder that is typically characterized by cardiomyopathy (CMP), skeletal myopathy, growth retardation, neutropenia, and increased urinary levels of 3‐methylglutaconic acid (3‐MGCA). There may be a wide variability of phenotypes amongst BTHS patients with some exhibiting some or all of these findings. BTHS was first described as a disease of the mitochondria resulting in neutropenia as well as skeletal and cardiac myopathies. Over the past few years, a greater understanding of BTHS has developed related to the underlying genetic mechanisms responsible for the disease. Mutations in the TAZ gene on chromosome Xq28, also known as G4.5, are responsible for the BTHS phenotype resulting in a loss‐of‐function in the protein product tafazzin. Clinical management of BTHS has also seen improvement. Patients with neutropenia are susceptible to life‐threatening bacterial infections with sepsis being a significant concern for possible morbidity and mortality. Increasingly, BTHS patients are suffering from heart failure secondary to their CMP. Left ventricular noncompaction (LVNC) and dilated CMP are the most common cardiac phenotypes reported and can lead to symptoms of heart failure as well as ventricular arrhythmias. Expanded treatment options for end‐stage myocardial dysfunction now offer an opportunity to change the natural history for these patients. Herein, we will provide a current review of the genetic and molecular basis of BTHS, the clinical features and management of BTHS, and potential future directions for therapeutic strategies. © 2013 The Authors. American Journal of Medical Genetics Part C: Seminars in Medical Genetics published by Wiley Periodicals, Inc.

1 February 2016 in Molecular Genetics and Metabolism
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Journal Article
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RHRobert J. Hopkin
Robert J. Hopkin
John Lynn JefferiesJohn Lynn Jefferies
John Lynn Jefferies
DLDawn A. Laney
Dawn A. Laney
VLVictoria H. Lawson
Victoria H. Lawson
MMMichael Mauer
Michael Mauer
WWWilliam R. Wilcox
William R. Wilcox

16 November 2021 in Journal of the American Heart Association
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Journal Article
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BMBrian W. McCrindle
Brian W. McCrindle
MAMichelson Alan
Michelson Alan
ABAndrew H. Van Bergen
Andrew H. Van Bergen
EHEstela Suzana Horowitz
Estela Suzana Horowitz
JSJuan Pablo Sandoval
Juan Pablo Sandoval
TSThierry Sluysmans
Thierry Sluysmans
Background: Patients with single‐ventricle physiology who undergo the Fontan procedure are at risk for thrombotic events associated with significant morbidity and mortality. The UNIVERSE Study evaluated the efficacy and safety of a novel liquid rivaroxaban formulation, using a body weight–adjusted dosing regimen, versus acetylsalicylic acid (ASA) in children post‐Fontan. Methods and Results: The UNIVERSE Study was a randomized, multicenter, 2‐part, open‐label study of rivaroxaban, in children who had undergone a Fontan procedure, to evaluate its dosing regimen, safety, and efficacy. Part A was the single‐arm part of the study that determined the pharmacokinetics/pharmacodynamics and safety of rivaroxaban in 12 participants before proceeding to part B, whereby 100 participants were randomized 2:1 to open‐label rivaroxaban versus ASA. The study period was 12 months. A total of 112 participants were enrolled across 35 sites in 10 countries. In part B, for safety outcomes, major bleeding occurred in one participant on rivaroxaban (epistaxis that required transfusion). Clinically relevant nonmajor bleeding occurred in 6% of participants on rivaroxaban versus 9% on ASA. Trivial bleeding occurred in 33% of participants on rivaroxaban versus 35% on ASA. For efficacy outcomes, 1 participant on rivaroxaban in part B had a pulmonary embolism (2% overall event rate); and for ASA, 1 participant had ischemic stroke and 2 had venous thrombosis (9% overall event rate). Conclusions: In this study, participants who received rivaroxaban for thromboprophylaxis had a similar safety profile and fewer thrombotic events, albeit not statistically significant, compared with those in the ASA group. Registration: URL: https://www.clinicaltrials.gov . Identifier: NCT02846532.