Medical Sciences Commons^™

The Frequency Of Pathogenic Variation In The All Of Us Cohort Reveals Ancestry-Driven Disparities, Eric Venner, Karynne Patterson, Divya Kalra, Marsha M Wheeler, Yi-Ju Chen, Sara E Kalla, Bo Yuan, Jason H Karnes, Kimberly Walker, Joshua D Smith, Sean Mcgee, Aparna Radhakrishnan, Andrew Haddad, Philip E Empey, Qiaoyan Wang, Lee Lichtenstein, Diana Toledo, Gail Jarvik, Anjene Musick, Richard A Gibbs

Journal Articles

Disparities in data underlying clinical genomic interpretation is an acknowledged problem, but there is a paucity of data demonstrating it. The All of Us Research Program is collecting data including whole-genome sequences, health records, and surveys for at least a million participants with diverse ancestry and access to healthcare, representing one of the largest biomedical research repositories of its kind. Here, we examine pathogenic and likely pathogenic variants that were identified in the All of Us cohort. The European ancestry subgroup showed the highest overall rate of pathogenic variation, with 2.26% of participants having a pathogenic variant. Other ancestry groups …

Genome-Wide Association Analysis Identifies Ancestry-Specific Genetic Variation Associated With Acute Response To Metformin And Glipizide In Sugar-Mgh, Josephine H Li, Laura N Brenner, Varinderpal Kaur, Katherine Figueroa, Philip Schroeder, Alicia Huerta-Chagoya, Miriam S Udler, Aaron Leong, Josep M Mercader, Jose C Florez

Journal Articles

AIMS/HYPOTHESIS: Characterisation of genetic variation that influences the response to glucose-lowering medications is instrumental to precision medicine for treatment of type 2 diabetes. The Study to Understand the Genetics of the Acute Response to Metformin and Glipizide in Humans (SUGAR-MGH) examined the acute response to metformin and glipizide in order to identify new pharmacogenetic associations for the response to common glucose-lowering medications in individuals at risk of type 2 diabetes.

METHODS: One thousand participants at risk for type 2 diabetes from diverse ancestries underwent sequential glipizide and metformin challenges. A genome-wide association study was performed using the Illumina Multi-Ethnic Genotyping …

Risk Factors For Thoracic Aortic Dissection, Zhen Zhou, Alana C Cecchi, Siddharth K Prakash, Dianna M Milewicz

Journal Articles

Thoracic aortic aneurysms involving the root and/or the ascending aorta enlarge over time until an acute tear in the intimal layer leads to a highly fatal condition, an acute aortic dissection (AAD). These Stanford type A AADs, in which the tear occurs above the sinotubular junction, leading to the formation of a false lumen in the aortic wall that may extend to the arch and thoracoabdominal aorta. Type B AADs originate in the descending thoracic aorta just distal to the left subclavian artery. Genetic variants and various environmental conditions that disrupt the aortic wall integrity have been identified that increase …

A Genome-Wide Association Study Of Obstructive Heart Defects Among Participants In The National Birth Defects Prevention Study, Sara R Rashkin, Mario Cleves, Gary M Shaw, Wendy N Nembhard, Eirini Nestoridi, Mary M Jenkins, Paul A Romitti, Xiang-Yang Lou, Marilyn L Browne, Laura E Mitchell, Andrew F Olshan, Kevin Lomangino, Sudeepa Bhattacharyya, John S Witte, Charlotte A Hobbs

Journal Articles

Obstructive heart defects (OHDs) share common structural lesions in arteries and cardiac valves, accounting for ~25% of all congenital heart defects. OHDs are highly heritable, resulting from interplay among maternal exposures, genetic susceptibilities, and epigenetic phenomena. A genome-wide association study was conducted in National Birth Defects Prevention Study participants (N

Vascular Disease Pathogenesis In Smooth Muscle Dysfunction Syndrome And Majewski Osteodysplastic Primordial Dwarfism Type Ii, Jamie Wright

Dissertations & Theses (Open Access)

Vascular diseases are a leading cause of morbidity and mortality world-wide. Understanding their pathogenesis is crucial to better diagnosis and management of these life-threatening conditions. Through the study of rare mutations that lead to early onset and severe vascular diseases, we can elucidate underlying mechanisms for vascular disease pathogenesis and develop better treatments to prevent and manage more common causes of vascular diseases. In this study we look at two rare diseases that lead to severe vascular phenotypes, Smooth Muscle Dysfunction Syndrome (SMDS) and Majewski Osteodysplastic Primordial Dwarfism Type II (MOPDII). SMDS is a rare condition due to pathogenic variants …

Genetics In The Nicu: Nurses’ Perceived Knowledge And Desired Education, Kathleen Shields

Dissertations & Theses (Open Access)

A large proportion of infants admitted to neonatal intensive care units (NICUs) have genetic conditions. NICU nurses play an important role in providing comprehensive care to these patients and their families. Previous research has demonstrated gaps exist in the genetics knowledge of nurses and that they lack comfort applying genetics information to clinical practice, but no research has been done assessing the knowledge of or comfort with genetics of NICU nurses specifically. NICU nurses (n=122) completed an online survey assessing their perceived knowledge of genetics, comfort with clinical scenarios involving genetics, and desired genetics education. Participants reported the highest levels …

Genetic Counselors' Experiences With And Approaches To Discordant Genotypic And Phenotypic Sex Detected Via Non-Invasive Prenatal Testing, Emily Stiglich

Dissertations & Theses (Open Access)

As the use of non-invasive prenatal testing becomes more ubiquitous during pregnancy, genetic counselors (GCs) will see clients more frequently for discordant sex identification via non-invasive prenatal testing (NIPT-DSI). Thus, it is imperative to investigate what GCs consider important when counseling about NIPT-DSI and assess how GCs perceive their role in such cases. Prenatal and pediatric GCs were surveyed regarding previous experiences of NIPT-DSI, comfort levels of topics relating to NIPT-DSI, and perceived importance of potential discussion topics in a counseling session (n = 108). The survey consisted of two vignettes, presenting cases of NIPT-DSI identified prenatally in one …

Genetic Counselors' Approaches To Direct-To-Consumer Genetic Testing For Hereditary Breast Cancer, Sarah Burke

Dissertations & Theses (Open Access)

Given the increasing availability of health-related direct-to-consumer genetic testing (DTC-GT) and third-party interpretation (TPI) services, it is likely that genetic counselors (GCs) will continue to encounter consumers that require follow-up counseling for their results. The National Comprehensive Cancer Network recommends clinical-grade genetic testing to confirm commercial results; however, the type of testing that GCs select remains uncharacterized. Therefore, we aimed to describe the specific recommendations that cancer GCs make for confirmatory genetic testing in probands who have already obtained DTC-GT results or TPI data that reported a BRCA1/2 pathogenic variant. We recruited 80 GCs specializing in hereditary cancer and administered …

Investigating Medical Examiners' Practices: Genetic Evaluation For Fatal Acute Aortic Dissection, Bradley Power

Dissertations & Theses (Open Access)

Acute thoracic aortic dissection (TAD) is a life-threatening event with a hereditary component. Currently, pathogenic variants in 11 genes associated with aortic aneurysm and dissection predispose to a heritable form of disease thereby conferring an increased risk for TAD. Genetic testing plays a pivotal role not only in diagnosis, but also in risk stratification for relatives and medical management to prevent premature death from dissection. Due to its high fatality rate, medical examiners and coroners (ME/Cs) may be the first to identify TAD cases and initiate genetic testing for the decedent and at-risk relatives. ME/Cs were surveyed using three clinical …

Frequency Of Copy Number Variants Involving The Sex Chromosomes In A Clinical Setting, Autumn Vara

Dissertations & Theses (Open Access)

Copy number variants (CNVs) are a common finding in the clinical setting and contribute to both genetic variation as well as disease. Recently, studies have described the accumulation of multiple CNVs as a disease modifying mechanism. While it has been characterized how additional CNVs may play a role in phenotype, in which ways and to what extent sex chromosomes are involved has not been fully described. We performed a secondary data analysis using the DECIPHER database on 2,273 de-identified individuals with 2 CNVs. CNVs were designated primary and secondary based on our criteria and characteristics of both CNV groups were …

Identification And Molecular Analysis Of Dna In Exosomes, Jena Tavormina

Dissertations & Theses (Open Access)

Exosomes are heterogeneous nanoparticles 50-150nm in diameter. Exosomes contain many functional cargo components, such as protein, DNA, and RNA. While protein and RNA exosome content has been extensively studied, very little work has been done to characterize exosomal DNA. Here, we demonstrate that exosomal DNA is heterogeneous and its packaging into exosomes is dependent on the cell of origin. Furthermore, through a rigorous assessment of various isolation methods, we identify Size Exclusion Chromatography (SEC) as the best method for the isolation of exosomal DNA for downstream applications. Additionally, we evaluate the methylation status of exosomal DNA and demonstrate that exosomal …

The Impacts Of Insurance And Billing Considerations On The Practice And Attitudes Of Genetic Counselors, Emily Krosschell

Dissertations & Theses (Open Access)

Genesurance counseling has been identified as an integral part of many genetic counseling sessions, but little is known about the workflow impacts and genetic counselor perceptions of genesurance-related tasks. In this study, we aimed to characterize how insurance and billing considerations for genetic testing are being incorporated into genetic counselors’ practice; as well as describe current attitudes and challenges associated with their integration. An electronic survey was sent by email to members of the National Society of Genetic Counselors (NSGC). A total of 325 genetic counselors that provided direct patient care were included in data analysis. Results showed that the …

Exploring The Potential Yield Of Prenatal Testing By Evaluating A Postnatal Population With Structural Abnormalities, Peyton Busby

Dissertations & Theses (Open Access)

After identification of one or more structural abnormalities in a fetus, pregnant women are offered a host of different testing options to identify a possible genetic cause for the structural abnormality(ies). When considering what type of test to undertake, there is limited information on the diagnostic yield of the varying testing options. Some women may miss an opportunity to gain the information they are seeking or make a less informed decision when they choose a testing option after identification of a structural abnormality due to this lack of information. This study aimed to identify the potential diagnostic yield of all …

Tumor Immunotherapy: Mechanisms Of Acquired Resistance And Characterization Of Immune Related Toxicities, Ashvin Jaiswal

Dissertations & Theses (Open Access)

Tumor immunotherapy has shown very promising clinical benefit across an array of cancers; however, two major challenges remain unresolved in the field. First, many patients do not respond to therapy at all or relapse after a period of remission. Second, there are often dose-limiting immune related adverse effects associated with immunomodulation.

In order to understand the mechanisms employed by tumors to evade immunotherapeutic responses, we established a murine model of melanoma designed to elucidate the molecular mechanisms underlying immunotherapy resistance. Through multiple in vivo passages, we selected a B16 melanoma tumor line that evolved complete resistance to combination blockade of …

Outcomes Of Genetic Testing In A Genitourinary Genetics Clinic, Annelise Pace

Dissertations & Theses (Open Access)

Several known hereditary cancer syndromes confer an increased risk for genitourinary (GU)related malignancies. Various guidelines indicate when to refer patients to genetic counseling for GU-related hereditary cancer syndromes but there is limited research on the clinical picture of these patients, including their cancerous and non-cancerous features, the genetic testing strategy for this population, and the probability of having a positive germline mutation if testing is performed. The purpose of this study is to determine the most common indications for ordering genetic testing in a GU Genetics Clinic and evaluate whether there is a relationship between the indication for genetic testing …

Managing Variant Discrepancy In Hereditary Cancer: Clinical Practice, Barriers, And Desired Resources, Ellen Zirkelbach

Dissertations & Theses (Open Access)

Variants are changes in the DNA whose phenotypic effects may or may not be definitively understood. Because variant interpretation is a complex process, sources sometimes disagree on the classification of a variant, which is called a variant discrepancy. This study aimed to determine the practice of genetic counselors regarding variant discrepancies and to identify the barriers to counseling a variant discrepancy in hereditary cancer genetic testing. This investigation was unique because it was the first to address variant discrepancies from a clinical point of view. An electronic survey was sent to genetic counselors in the NSGC Cancer Special Interest Group. …

Genesurance Counseling: Patient Perspectives, Chelsea Wagner

Dissertations & Theses (Open Access)

Genetic counselors (GCs) have recently reported an increase in the discussion of insurance-related, or “genesurance,” topics during genetic counseling sessions. Despite increasing frequency, little knowledge exists about genesurance conversations and patient expectations. This study aimed to assess patient expectations of GCs in genesurance discussions and evaluate if health insurance literacy impacted these expectations. A 38-item survey, including a validated tool to assess health insurance literacy (HIL) was administered prior to patients receiving prenatal or cancer genetic counseling at three participating institutions. A total of 360 responses were analyzed. Key variables were compared using chi-square analysis and multivariable logistic regression was …

The Utilization Of Prenatal Microarray: A Survey Of Current Genetic Counseling Practices And Barriers, Leslie N. Durham, Leslie Durham

Dissertations & Theses (Open Access)

Chromosomal microarray (CMA) assesses chromosome copy number variants (CNVs) missed by standard karyotyping. The American College of Obstetricians and Gynecologists (ACOG) recommends CMA for all patients with fetuses with an ultrasound anomaly and suggests that it be made available to all women undergoing invasive testing. In order to assess prenatal genetic counselors’ (GCs) practices regarding the utilization of CMA we conducted a survey of their current practices, attitudes, and perceived barriers. Of the 192 respondents, 183 (95%) have incorporated CMA into clinical practice with the majority (64%) believing that the benefits of CMA outweigh the harms. However, only half (52%) …

Ethnic Identity And Teratogenic Risk Perceptions, Katie M. Chan

Dissertations & Theses (Open Access)

Elevated perceptions of teratogenic risk can cause anxiety and confusion among pregnant women. To assess whether ethnic identity and demographic factors can influence teratogenic risk perceptions, 194 pregnant women in Houston were surveyed using the Multigroup Ethnic Identity Measure (MEIM) and visual analog scales to quantify perceptions of teratogenic risk for common exposures during pregnancy. Overall, participants estimated an elevated baseline risk of 25% for birth defects among the general population. In addition, participants overestimated birth defect risks for specific exposures, such as alcohol and marijuana. Based on the MEIM scores, ethnic identity was not significantly associated with teratogenic risk …

No Difference In Health Related Quality Of Life Between Therapeutic Options For Type 1 Gaucher Disease, Victoria Wagner

Dissertations & Theses (Open Access)

Type 1 Gaucher disease (GD) is the most common lysosomal storage disorder. Previously, treatment for GD was limited to intravenous enzyme replacement therapy (ERT). ERT reduces symptoms and increases health­related quality of life (HRQoL) in people with this condition. In 2014, oral substrate reduction therapy (SRT) was approved for type 1 GD treatment. Although both therapies alleviate disease symptoms, effects of SRT on HRQoL and preferences for therapy are not well established. Electronic surveys were administered to adults with type 1 GD. HRQoL was scored with the Short Form­36 Version 2 ® Health Survey and descriptive statistics were used to …

Factors Influencing Uptake Of Risk-Reducing Salpingo-Oophorectomy By Brca1 And Brca2 Mutation Carriers, Victoria E. Breen

Dissertations & Theses (Open Access)

Germline mutations in the BRCA1 and BRCA2 genes are associated with significantly increased risks for ovarian cancer. The National Comprehensive Cancer Network (NCCN) currently recommends that female BRCA mutation carriers undergo risk-reducing salpingo-oophorectomy (RRSO) after age 35; however, not all women elect this option. The purpose of this study was to prospectively survey women with BRCA mutations currently undergoing ovarian cancer screening about their intention to have an RRSO and the various factors influencing their decision. Of the 26 women who completed our survey, 26 (100%, CI: 86.8-100) plan to undergo an RRSO in their lifetime. The average woman reported …

Obstetrician And Gynecologist Utilization Of The Nipt Expanded Testing Option, Sarah Mayes Ba

Dissertations & Theses (Open Access)

Noninvasive prenatal testing (NIPT) enables the detection of common fetal aneuploidies such as trisomy 21, trisomy 18, trisomy 13, and sex chromosome abnormalities via analysis of cell-free fetal DNA circulating in maternal serum. Although the accuracy of NIPT for fetal aneuploidy is expected to be higher than that of currently available alternative maternal serum screening options, the implications of results are not straight forward. In October 2013, the option to screen for additional trisomies and select microdeletion syndromes, such as 22q11.2 deletion syndrome and 5 p- syndrome, became clinically available. Due to this rapidly evolving prenatal screening technology, clinicians must …

Genetics Of Obesity In Starr County, Texas Mexican Americans, Heather M. Highland

Dissertations & Theses (Open Access)

Currently, over two-thirds of Americans are classified as over-weight or obese. Obesity increases risk for many other diseases including type 2 diabetes, heart disease, stroke, and cancer, making obesity the largest public health problem in America and most other Westernized nations. Hispanics have a higher rate of both obesity and type 2 diabetes, making them a particularly interesting population in which to study obesity. For the last 33 years, the Starr County Health Studies has collected an array of phenotypes and biological samples from residents of Starr County, along Texas-Mexico border. This study includes 825 subjects who were not known …

Cancer Incidence In First And Second Degree Relatives Of Brca1 And Brca2 Mutation Carriers, Haley Streff

Dissertations & Theses (Open Access)

Mutations in the BRCA1 or BRCA2 genes are associated with increased risks for breast, ovarian, and several other cancers. The purpose of this study was to evaluate the incidence of cancers in first and second degree relatives of BRCA mutation carriers compared to the general population. A total of 1086 pedigrees of BRCA mutation carriers were obtained from a prospectively maintained, internal review board approved study of persons referred for clinical genetic counseling at The University of Texas MD Anderson Cancer Center. We identified 9032 first and second degree relatives from 784 pedigrees which demonstrated a clear indication of parental …

Correlation Matrix Analysis Identifies Gene Signatures Of Immune Cell Subsets And Their Interactions In Follicular Lymphoma, Jason R. Westin

Dissertations & Theses (Open Access)

There are important but ill-defined interactions between benign immune cell subsets and neoplastic B cells within follicular lymphoma (FL). Using the novel technique of correlation matrix analysis (CMA) of publicly available FL whole-tumor gene expression profiling (GEP) data, we have identified signatures of immune cell subsets. Overall survival correlated most highly with a model using signatures of macrophages, T cells, and stroma, which was able to add significantly to existing clinical prognostic tools. From our own data of a cohort of 43 FL tumors sorted into B-cell and non-B cell (NB) fractions for GEP, CMA of the tumor infiltrating NB …

Dissecting The Roles Of Trim24 In Regulation Of Hepatic Lipid Metabolism And Inflammation, Lindsey C. Minter

Dissertations & Theses (Open Access)

DISSECTING THE ROLES OF TRIM24 IN REGULATION OF HEPATIC LIPID

METABOLISM AND INFLAMMATION

Lindsey Cauthen Minter, B.S., B.A.

Advisory Professor: Michelle C. Barton, Ph.D.

In this dissertation, I report the characterization of a new mouse model that recapitulates development of hepatocellular carcinoma (HCC) following spontaneous hepatic lipid accumulation, inflammation, and damage of liver tissue, due to complete loss of Trim24 expression. In human HCC and other cancers, TRIM24 expression is aberrantly high, while deletion of TRIM24 in the mouse has been shown to act as a liver specific tumor suppressor. The hypothesis tested here was that TRIM24, the E3 ubiquitin …

Availability Of Dental Anomaly Phenotype In Individuals With Familial Adenomatous Polyposis, Andrea M. Lewis

Dissertations & Theses (Open Access)

Background: Mutations in the APC gene cause familial adenomatous polyposis (FAP), an autosomal dominant colorectal cancer predisposition associated with the development of hundreds to thousands of adenomatous colorectal polyps beginning in childhood or adolescence. Both malignant and non-malignant extracolonic manifestations are associated with APC gene mutations, including approximately 17% of individuals with various dental anomalies. The availability of dental anomaly information in the medical record remains to be evaluated.

Methods: Medical records were reviewed for documentation of dental anomalies. Dental questionnaires were mailed to 271 individuals with FAP at The University of Texas M. D. Anderson Cancer Center (UTMDACC) to …

Latinas And The Traditional Genetic Counseling Model: A Qualitative Study, Stephanie Thompson

Dissertations & Theses (Open Access)

The traditional genetic counseling model reflects an individualized counseling session that includes the presentation of information about genes, chromosomes, personalized risk assessment, and genetic testing and screening options. Counselors are challenged to balance providing educational information with discussion of implications of this information in an allotted amount of time. The aim of this study was to explore the perceptions of pregnant Latinas on the benefits and limitations of the traditional prenatal genetic counseling model and to determine the specific preferences for receiving prenatal genetic counseling. Data were collected through focus groups and one-on-one, semi-structured interviews of twenty-five Spanish speaking Latinas …

Evaluation Of Current Clinical Criteria For Li-Fraumeni Syndrome In A Diverse Sample Of Tp53 Mutation Carriers, Emily A. Parham

Dissertations & Theses (Open Access)

Li-Fraumeni syndrome (LFS) is a hereditary cancer predisposition syndrome caused by heterozyogous germline mutations in the TP53 gene and characterized by an excess of early-onset cancers, high lifetime risk of cancer, and a wide range of tumor types. Recent studies suggesting a benefit in comprehensive screening protocols for both children and adults make the timely identification of individuals with LFS increasingly important.

A number of criteria have been proposed to identify patients with LFS. The National Comprehensive Cancer Network (NCCN) combines several in its Clinical Practice Guidelines for TP53 genetic testing. Prior studies have shown that the cumulative sensitivity of …

Differential Regulation Of Iress In The Aurora A Mrna By Bfgf Through The Mtor Complex Torc2 Modulates Aurora A Kinase Expression, Roy L. Voice Iii

Dissertations & Theses (Open Access)

Identifying the mechanisms that contribute to tumorigenesis is a major area of focus in our fight against cancer. Epithelial malignant tumors, such as breast, colon, ovarian and pancreatic cancers have been shown to overexpress proteins that control cell mitosis, growth, and proliferation. One of those proteins is the Aurora A kinase. Aurora A kinase is a member of a small family of kinases that contribute to mitotic events such as centrosome duplication, separation, and maturation. Aurora A overexpression leads to genomic instability, which can contribute to tumorigenesis, on the other hand, inhibiting Aurora A expression leads to apoptosis, making it …