Genetics and Genomics Commons^™

Targeting Metabolic Alterations Associated With Smooth Muscle Α-Actin Pathogenic Variant Attenuates Moyamoya-Like Cerebrovascular Disease, Anita Kaw

Dissertations and Theses (Open Access)

Heterozygous pathogenic variants in ACTA2, encoding smooth muscle α-actin (α-SMA), predispose to thoracic aortic aneurysms and dissections. De novo missense variants disrupting ACTA2 arginine 179 (p.Arg179) cause a multisystemic disease termed smooth muscle dysfunction syndrome (SMDS), which is characterized by early onset thoracic aortic disease and moyamoya disease-like (MMD) cerebrovascular disease. The MMD-like cerebrovascular disease in SMDS patients is marked by bilateral steno-occlusive lesions in the distal internal carotid arteries (ICAs) and their branches. To study the molecular mechanisms that underlie the ACTA2 p.Arg179 variants, a smooth muscle-specific Cre-lox knock-in mouse model of the heterozygous Acta2 R179C variant, termed …

Deephtlv: A Deep Learning Framework For Detecting Human T-Lymphotrophic Virus 1 Integration Sites, Johnathan Jia, Johnathan Jia

Dissertations and Theses (Open Access)

In the 1980s, researchers found the first human oncogenic retrovirus called human T-lymphotrophic virus type 1 (HTLV-1). Since then, HTLV-1 has been identified as the causative agent behind several diseases such as adult T-cell leukemia/lymphoma (ATL) and a HTLV-1 associated myelopathy or tropical spastic paraparesis (HAM/TSP). As part of its normal replication cycle, the genome is converted into DNA and integrated into the genome. With several hundreds to thousands of unique viral integration sites (VISs) distributed with indeterminate preference throughout the genome, detection of HTLV-1 VISs is a challenging task. Experimental studies typically use molecular biology …

Regulation Of De Novo And Maintenance Dna Methylation By Dnmt3a And Dnmt3b, Yang Zeng

Dissertations and Theses (Open Access)

DNA methylation (5-methylcytosine, 5mC) is essential for the regulation of gene expression and integrity of the mammalian genome. It occurs predominantly in the context of CpG dinucleotides to form a symmetrical pattern on both DNA strands, which allows DNA methylation patterns to be semi-conservatively maintained during DNA replication. There are two classes of DNA methyltransferases (DNMTs): DNMT3A and DNMT3B function primarily as de novo methyltransferases that establish DNA methylation patterns, whereas DNMT1 is the major enzyme responsible for maintaining DNA methylation patterns by converting hemi-methylated CpGs to fully methylated CpGs during DNA replication. Two accessory factors also play critical regulatory …

Prenatal Screening Decision-Making Facilitated Through An Online Patient Education Module, Erin Atkinson

Dissertations and Theses (Open Access)

As recommendations for prenatal genetic screening are expanded to include patients with pregnancies at low risk for aneuploidy, there is a need to develop accessible mechanisms to promote informed decision-making about genetic screening. The use of patient decision aids has been shown to promote informed decision-making. UTHealth Houston has developed and implemented an online module for pre-test triage for genetic counseling and education of low-risk pregnant patients about genetic screening, called the Prenatal Genetic Education Program (PGEP).

Here, through a retrospective chart review, we characterize the use of PGEP to triage previously presumed low-risk patients to genetic counseling, and whether …

The Need For Racial And Ethnic Health Disparity Curriculum In Genetic Counseling Programs, Yusra Aziz

Dissertations and Theses (Open Access)

Racial and ethnic health disparities (REHD) exist across all organized medicine, including the spectrum of genetic counseling, particularly in genomic testing and access to care. While cultural competency and health disparities have been included as a part of the Standards of Accreditation for Genetic Counseling, there have not been previous efforts to define what topics related to REHD are most important to include in graduate program curriculum. Therefore, this study aimed to determine what topics related to REHD should be taught in genetic counseling program curriculum by assessing what topics genetic counselors (GCs) learned about and in what settings, …

Genetic Regulation Of Müllerian Duct Regression, Malcolm Moses

Dissertations and Theses (Open Access)

Mammals, including humans, develop progenitor tissues for both male and female reproductive tract organs before they fully differentiate into a male or female tract. The progenitor tissue for the male reproductive tract is known as the Wolffian duct (WD), and the progenitor tissue for the female reproductive tract is the Müllerian duct (MD). The WD further differentiates into the vas deferens, epididymis, and seminal vesicle, while the MD differentiates into the oviduct, uterus and upper vagina. An essential step in sex differentiation for males is the regression of the MD. This regression initiates with anti-Müllerian hormone (Amh) transcription …

Functions Of The Trna Splicing Endonuclease And Other Adventures In Rna Processing, Jennifer Hurtig, Ambro Van Hoof

Dissertations and Theses (Open Access)

The tRNA splicing endonuclease (TSEN), has been studied for over three decades for its function in tRNA splicing. However, this enzyme has other functions that are just beginning to be characterized. Mutations in TSEN cause the neuronal disease pontocerebellar hypoplasia (PCH) that is characterized by atrophy of the cerebellum and pons, overall developmental failure, and usually results in death before adolescence. How mutations in TSEN cause these neuronal defects and disease is not understood. In yeast, TSEN has another essential function that is independent of tRNA splicing and is still unknown. In this thesis I strived to understand the other …

Dna Methylation Analysis Is Used To Identify Novel Genetic Loci Associated With Circulating Fibrinogen Levels In Blood, Julie Hahn, Jan Bressler, Arce Domingo-Relloso, Ming-Huei Chen, Daniel L Mccartney, Alexander Teumer, Jenny Van Dongen, Marcus E Kleber, Dylan Aïssi, Brenton R Swenson, Jie Yao, Wei Zhao, Jian Huang, Yujing Xia, Michael R Brown, Ricardo Costeira, Eco J C De Geus, Graciela E Delgado, Dre'von A Dobson, Paul Elliott, Hans J Grabe, Xiuqing Guo, Sarah E Harris, Jennifer E Huffman, Sharon L R Kardia, Yongmei Liu, Stefan Lorkowski, Riccardo E Marioni, Matthias Nauck, Scott M Ratliff, Maria Sabater-Lleal, Tim D Spector, Pierre Suchon, Kent D Taylor, Florian Thibord, David-Alexandre Trégouët, Kerri L Wiggins, Gonneke Willemsen, Jordana T Bell, Dorret I Boomsma, Shelley A Cole, Simon R Cox, Abbas Dehghan, Andreas Greinacher, Karin Haack, Winfried März, Pierre-Emmanuel Morange, Jerome I Rotter, Nona Sotoodehnia, Maria Tellez-Plaza, Ana Navas-Acien, Jennifer A Smith, Andrew D Johnson, Myriam Fornage, Nicholas L Smith, Alisa S Wolberg, Alanna C Morrison, Paul S De Vries

Faculty, Staff and Student Publications

Background:

Fibrinogen plays an essential role in blood coagulation and inflammation. Circulating fibrinogen levels may be determined by inter-individual differences in DNA methylation at CpG sites, and vice versa.

Methods:

We performed an epigenome-wide association study (EWAS) of circulating fibrinogen levels in 18,037 White, Black, American Indian, and Hispanic participants representing 14 studies from the CHARGE consortium. Circulating leukocyte DNA methylation was measured in 12,904 participants using the Illumina 450K array, and in 5,133 participants using the EPIC array. Each study performed an EWAS of fibrinogen using linear mixed models adjusted for potential confounders. Study-specific results were combined using array-specific …

Acetate Metabolism In The Fungal Pathogen Cryptococcus Neoformans, Oly Ahmed

All Dissertations

Cryptococcus neoformans is an environmental basidiomycetous fungus with a worldwide distribution and a wide range of habitats. Inhalation of the desiccated yeasts or spores of C. neoformans often leads to opportunistic pulmonary infections in immunocompromised individuals, and in severe cases causes lethal meningitis following hematogenous dissemination. During infection, depending on the tissue and disease state, the invading fungi experience a range of nutrient microenvironments within the host body. As a result, rapid metabolic adaptations geared towards efficient utilization of carbon sources alternative to glucose become one of the prime determinants of survival and growth for the pathogen. Incidentally, cryptococcal infection …

Diagnosis Of Urinary Tract Infections And Rapid Molecular Characterization Of Antibiotic Resistance, Mohammed Harris

All Dissertations

Urinary tract infections (UTIs) are one of the most common infectious clinical entities in both community and hospital settings. They have a broad range of clinical severity yet inflict large epidemiological burden of morbidity and mortality on patients and the healthcare system with billions of dollars in cost of treatment. Understanding what methods are optimal for diagnosing UTIs are critical to mitigate the marked impact and cost of these infections.

Chapter 1 and 2 in this work surveys the broad array of diagnostic modalities for UTIs and highlights their advantages and limitations in the context of the current standard of …

Development Of A Novel Environmental Dna (Edna) Tool For Monitoring Vulnerable Freckled Guitarfish, Pseudobatos Lentiginosus, In The Western Central Atlantic, Sarah Toepfer

Honors Theses

Rhino-rays are the most threatened group of elasmobranchs, having experienced widespread declines due to mortalities in fisheries and habitat degradation. Within the Western Central Atlantic, there are two extant species of Rhino-rays, the Critically Endangered Smalltooth Sawfish, Pristis pectinata, and the Vulnerable Freckled Guitarfish, Pseudobatos lentiginosus. Although there is research committed to P. pectinata in this region, less is known about the distribution status of P. lentiginosus. Over the past 50 years, P. lentiginosus have undergone a presumed range contraction in U.S. waters; once found from North Carolina to Texas, and historically common in the north central …

A Multi-Pronged Investigation To Identify Genes Affecting The Autoregulation Of Nodulation: Lasercapture Microdissection And The Barely Any Meristem Gene Family In Medicago Truncatula, Jacklyn Thomas

All Dissertations

The unique evolutionary adaptation of legumes for nitrogen-fixing symbiosis leading to nodulation is tightly regulated by the host plant. One pathway negatively regulates the number of nodules formed in response to the metabolic status of the shoot (carbon) and root (nitrogen); this long-distance systemic regulation is the autoregulation of nodulation (AON) pathway. AON is a root to shoot pathway that allows the plant to limit the number of nodules formed on roots. Central to the receptor complex in the shoots is a leucine-rich-repeat receptor-like kinase (LRR-RLK) called MtSUNN mutation of which results in plants with too many nodules. SUNN …

Methyltransferase, Glucose Adaptation, And Import Complex In Trypanosoma Brucei, Emily Knight

All Dissertations

Trypanosoma brucei is a kinetoplastid parasite responsible for human African trypanosomiasis (HAT) and nagana, a livestock wasting disease, which both endemic to sub-Saharan Africa. Unique to kinetoplastids are the specialized peroxisomes, named glycosomes, which compartmentalize the first several steps of glycolysis and gluconeogenesis, nucleotide sugar biosynthesis, and many other metabolic processes. Kinetoplastids are unique in that they have a single mitochondrion. In this work, I present the first study into SET domain proteins in any kinetoplastid parasites. We have characterized a predicted SET domain protein, TbSETD3, that localizes to the mitochondrion and a depletion of the protein results in growth …

Landscape Genetics Of The Gulf Coast Tick, Amblyomma Maculatum, Sara Simmons Benham

Biological Sciences Theses & Dissertations

Connectivity among populations helps to maintain genetic diversity, population stability, and resilience. The Gulf Coast tick, Amblyomma maculatum, is a vector of the pathogen Rickettsia parkeri. Persistence of tick populations with high rates of R. parkeri infection poses health risks to humans and animals. Mitochondrial haplotypes were characterized by sequencing a fragment of the mitochondrial 16S rRNA gene. A comparative study of A. maculatum and Amblyomma americanum was conducted to identify similar and unique patterns between the species within the same region. Next, I compared A. maculatum sites across three different regions of the United States. This work …

A Weakly Structured Stem For Human Origins In Africa, Aaron P Ragsdale, Timothy D Weaver, Elizabeth G Atkinson, Eileen G Hoal, Marlo Möller, Brenna M Henn, Simon Gravel

Faculty, Staff and Students Publications

Despite broad agreement that Homo sapiens originated in Africa, considerable uncertainty surrounds specific models of divergence and migration across the continent1. Progress is hampered by a shortage of fossil and genomic data, as well as variability in previous estimates of divergence times1. Here we seek to discriminate among such models by considering linkage disequilibrium and diversity-based statistics, optimized for rapid, complex demographic inference2. We infer detailed demographic models for populations across Africa, including eastern and western representatives, and newly sequenced whole genomes from 44 Nama (Khoe-San) individuals from southern Africa. We infer a reticulated …

Functional Screening Of Lysosomal Storage Disorder Genes Identifies Modifiers Of Alpha-Synuclein Neurotoxicity, Meigen Yu, Hui Ye, Ruth B De-Paula, Carl Grant Mangleburg, Timothy Wu, Tom V Lee, Yarong Li, Duc Duong, Bridget Phillips, Carlos Cruchaga, Genevera I Allen, Nicholas T Seyfried, Ismael Al-Ramahi, Juan Botas, Joshua M Shulman

Faculty, Staff and Students Publications

Heterozygous variants in the glucocerebrosidase (GBA) gene are common and potent risk factors for Parkinson's disease (PD). GBA also causes the autosomal recessive lysosomal storage disorder (LSD), Gaucher disease, and emerging evidence from human genetics implicates many other LSD genes in PD susceptibility. We have systemically tested 86 conserved fly homologs of 37 human LSD genes for requirements in the aging adult Drosophila brain and for potential genetic interactions with neurodegeneration caused by α-synuclein (αSyn), which forms Lewy body pathology in PD. Our screen identifies 15 genetic enhancers of αSyn-induced progressive locomotor dysfunction, including knockdown of fly homologs of GBA …

Cascade Testing After Exome Sequencing: Retrospective Analysis Of Linked Family Data At 2 Us Laboratories, Julie Stefka, Haley Streff, Pengfei Liu, Meghan Towne, Hadley Stevens Smith

Faculty, Staff and Students Publications

Purpose: Cascade testing, the process of testing a proband's at-risk relatives, is integral to realizing the full value of genomic sequencing. However, there is little empirical evidence on the uptake of cascade testing after a positive exome sequencing (ES) result in a population of probands with diverse clinical indications.

Methods: We retrospectively reviewed administrative data from 2 US clinical laboratories that perform ES. For each proband with a positive ES result, we used linked family data to describe the frequency of relatives' cascade testing performed at the same laboratory, variant detection yield of cascade tests, and characteristics of probands and …

Exosomes, Microvesicles, And Other Extracellular Vesicles-A Keystone Symposia Report, Jennifer Cable, Kenneth W Witwer, Robert J Coffey, Aleksandar Milosavljevic, Ariana K Von Lersner, Lizandra Jimenez, Ferdinando Pucci, Maureen M Barr, Niek Dekker, Bahnisikha Barman, Daniel Humphrys, Justin Williams, Michele De Palma, Wei Guo, Nuno Bastos, Andrew F Hill, Efrat Levy, Michael P Hantak, Clair Crewe, Elena Aikawa, Alan M Adamczyk, Tamires M Zanotto, Matias Ostrowski, Tanina Arab, Daniel C Rabe, Aadil Sheikh, Danilo Rodrigues Da Silva, Jennifer C Jones, Chioma Okeoma, Thomas Gaborski, Qin Zhang, Olesia Gololobova

Faculty, Staff and Students Publications

Extracellular vesicles (EVs) are small, lipid-bilayer-bound particles released by cells that can contain important bioactive molecules, including lipids, RNAs, and proteins. Once released in the extracellular environment, EVs can act as messengers locally as well as to distant tissues to coordinate tissue homeostasis and systemic responses. There is a growing interest in not only understanding the physiology of EVs as signaling particles but also leveraging them as minimally invasive diagnostic and prognostic biomarkers (e.g., they can be found in biofluids) and drug-delivery vehicles. On October 30-November 2, 2022, researchers in the EV field convened for the Keystone symposium "Exosomes, Microvesicles, …

Biallelic Variants In Adamts15 Cause A Novel Form Of Distal Arthrogryposis, Felix Boschann, Ozgur Cogulu, Davut Pehlivan, Saranya Balachandran, Pedro Vallecillo-Garcia, Christopher M Grochowski, Nils R Hansmeier, Zeynep H Coban Akdemir, Cesar A Prada-Medina, Ayca Aykut, Björn Fischer-Zirnsak, Simon Badura, Burak Durmaz, Ferda Ozkinay, René Hägerling, Jennifer E Posey, Sigmar Stricker, Gabriele Gillessen-Kaesbach, Malte Spielmann, Denise Horn, Knut Brockmann, James R Lupski, Uwe Kornak, Julia Schmidt

Faculty, Staff and Student Publications

No abstract provided.

Epigenetic Age Acceleration Among Survivors Of Pediatric Medulloblastoma And Primitive Neuroectodermal Tumor, Rachel D Harris, Melissa A Richard, Maria Monica J Gramatges, Kevin Wilhelm, Michael E Scheurer, Philip J Lupo, Austin L Brown

Faculty, Staff and Students Publications

Survivors of childhood central nervous system (CNS) tumors experience early-onset aging-related phenotypes. DNA methylation (DNAm) age is an emerging epigenetic biomarker of physiologic age and may be predictive of chronic health conditions in long-term survivors. This report describes the course of epigenetic age acceleration using post-diagnosis blood samples (median: 3.9 years post-diagnosis; range: 0.04–15.96) from 83 survivors of pediatric CNS tumors. Epigenetic age acceleration was detected in 72% of patients, with an average difference between chronologic and dnam age of 2.58 years (95% Ci: 1.75–3.41, p < 0.001). Time from diagnosis to sample collection correlated with the magnitude of epigenetic age acceleration.