GUEVARA RAMÍREZ, ALEXANDRA PATRICIA

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Facultad de Ciencias de la Salud Eugenio Espejo

CIGG - Centro de Investigación Genética y Genómica

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ORCID

0000-0002-4829-3653

Scopus Author ID

57195725827

Now showing 1 - 10 of 69

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Characterization of a variant in the KCNH2 gene in an Ecuadorian patient with long QT syndrome: A case report
(Medwave Estudios Limitada, 2025-07-01)
CADENA ULLAURI, SANTIAGO ANDRE
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GUEVARA RAMIREZ, ALEXANDRA PATRICIA
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TAMAYO TRUJILLO, VICTOR RAFAEL
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Rita Ibarra Castillo
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José Luis Laso Bayas
Long QT syndrome is a rare cardiac channelopathy characterized by prolonged QT intervals and altered T wave morphology. The etiology of long QT syndrome is multifactorial, including environmental and genetic factors. In addition, several heart diseases have been associated with the individual's ethnicity. The objective of the present case report is to describe the genetic and clinical findings of a 44-year-old Ecuadorian man who experienced recurrent episodes of syncope, prolonged QT intervals, and emergent arrhythmias. Through next-generation sequencing, genetic analysis identified a p.Val612Met variant in the KCNH2 gene, associated with long QT syndrome type 2. These findings were key in classifying the patient’s condition as life-threatening and guiding the implementation of a personalized treatment strategy.
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Spectrum and Clinical Interpretation of TTN Variants in Ecuadorian Patients with Heart Disease: Insights into VUS and Likely Pathogenic Variants
(MDPI AG, 2025-12-10)
GUEVARA RAMÍREZ, ALEXANDRA PATRICIA
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CADENA ULLAURI, SANTIAGO ANDRÉ
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TAMAYO TRUJILLO, VICTOR RAFAEL
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RUIZ POZO, VIVIANA ALEJANDRA
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PAZ CRUZ, ELIUS ANDRES
This study described TTN gene variants in Ecuadorian patients with hereditary cardiac diseases, integrating genetic ancestry to improve variant interpretation in an underrepresented population. Sixty patients with confirmed hereditary cardiac conditions were analyzed using the TruSight Cardio NGS panel (Illumina, San Diego, CA, USA), which targets 174 cardiac-associated genes. Bioinformatic analyses and classification were performed in accordance with ACMG/AMP guidelines, and ancestry inference was conducted using 46 Ancestry Informative Markers (AIM-InDels). From 4008 detected TTN variants, 29 variants of interest remained after filtering: 27 classified as variants of uncertain significance (VUS) and two as likely pathogenic. All variants were heterozygous and distributed across exons 3–358, primarily in the A-band region, commonly associated with cardiomyopathies and arrhythmic phenotypes. Two truncating variants (exons 267 and 272) met PVS1 criteria, while several missense variants (p.Ser91Gly, p.Pro12140Ser, p.Arg34653Cys) showed possible modulatory effects on hypertrophic or arrhythmic outcomes. Genetic ancestry revealed a predominant Native American background, followed by European and African components. These findings expand the understanding of TTN-related cardiac disease in Latin America, suggesting that TTN functions as a genetic modifier influencing disease expression. Incorporating ancestry information enhances genomic interpretation and supports precision medicine in diverse populations.
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Molecular mechanisms of semaglutide and liraglutide as a therapeutic option for obesity
(Frontiers Media SA, 2024-04-29)
TAMAYO TRUJILLO, VICTOR RAFAEL
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RUIZ POZO, VIVIANA ALEJANDRA
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Raynier Zambrano-Villacres
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CADENA ULLAURI, SANTIAGO ANDRE
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GUEVARA RAMIREZ, ALEXANDRA PATRICIA
Obesity, a chronic global health problem, is associated with an increase in various comorbidities, such as cardiovascular disease, type 2 diabetes mellitus, hypertension, and certain types of cancer. The increasing global prevalence of obesity requires research into new therapeutic strategies. Glucagon-like peptide-1 receptor agonists, specifically semaglutide and liraglutide, designed for type 2 diabetes mellitus treatment, have been explored as drugs for the treatment of obesity. This minireview describes the molecular mechanisms of semaglutide and liraglutide in different metabolic pathways, and its mechanism of action in processes such as appetite regulation, insulin secretion, glucose homeostasis, energy expenditure, and lipid metabolism. Finally, several clinical trial outcomes are described to show the safety and efficacy of these drugs in obesity management.
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Case report: Genomic screening for inherited cardiac conditions in Ecuadorian mestizo relatives: Improving familial diagnose
(Frontiers Media SA, 2022-11-08)
CADENA ULLAURI, SANTIAGO ANDRE
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GUEVARA RAMIREZ, ALEXANDRA PATRICIA
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Tatiana Sánchez Insuasty
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Nieves Doménech
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RUIZ POZO, VIVIANA ALEJANDRA
<jats:sec><jats:title>Introduction</jats:title><jats:p>Genomic screening is an informative and helpful tool for the clinical management of inherited conditions such as cardiac diseases. Cardiac-inherited diseases are a group of disorders affecting the heart, its system, function, and vasculature. Among the cardiac inherited abnormalities, one of the most common is Wolff-Parkinson-White syndrome. Similarly, hypertrophic cardiomyopathy is another common autosomal dominant inherited cardiac disease. Hypertrophic cardiomyopathy is associated with an increased incidence of Wolff-Parkinson-White syndrome; reports have suggested that it could be caused by a mutation in the protein-coding gene PRKAG2, which encodes a subunit of the AMP-activated protein kinase.</jats:p></jats:sec><jats:sec><jats:title>Case presentation</jats:title><jats:p>A 37-year-old Ecuadorian male (Subject A) with familiar history of bradycardia, cardiac pacemaker implantation, and undiagnosed cardiac conditions began with episodes of tachycardia, dizziness, shortness of breath, and a feeling of fainting. He was diagnosed with hypertrophic myocardiopathy and Wolff Parkinson White preexcitation syndrome. Furthermore, his cousin's son, an 18-year-old Ecuadorian male (Subject B), started suffering from migraine and tachycardia at any time of the day. He was diagnosed with hypertrophic myocardiopathy; his electrocardiogram showed a systolic overload. Next-generation sequencing and ancestry analyses were performed. A c.905G&gt;A p.(Arg302Gln) mutation in the gene PRKAG2 and a mainly European composition were identified in both subjects.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>Genetic testing is a valuable tool as it can provide important information regarding a disease, including its cause and consequences, not only for single individuals but to identify at-risk relatives. Furthermore, NGS results could guide the physician into targeted therapy. In the present case report, a missense pathogenic Arg302Gln mutation in the PRKAG2 gene has been identified in two related Ecuadorian Subjects diagnosed with hypertrophic myocardiopathy and Wolff-Parkinson-White. The variant has not been reported in Latin America; hence, this is the first report of the Arg302Gln mutation in the PRKAG2 gene in mestizo Ecuadorian subjects with mainly European ancestry components.</jats:p></jats:sec>
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Genomic analysis of an Ecuadorian individual carrying an SCN5A rare variant
(Springer Science and Business Media LLC, 2024-07-27)
CADENA ULLAURI, SANTIAGO ANDRE
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GUEVARA RAMIREZ, ALEXANDRA PATRICIA
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Rita Ibarra-Castillo
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José Luis Laso-Bayas
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RUIZ POZO, VIVIANA ALEJANDRA
Background: Ion channels, vital transmembrane protein complexes, regulate ion movement within cells. Germline variants in channel-encoding genes lead to channelopathies. The sodium channels in cardiac cells exhibit a structure of an alpha subunit and one to two beta subunits. The alpha subunit, encoded by the SCN5A gene, comprises four domains. Case presentation: A fifteen-year-old Ecuadorian female with atrial flutter and abnormal sinus rhythm with no familial history of cardiovascular disease underwent NGS with the TruSight Cardio kit (Illumina). A likely pathogenic SCN5A gene variant (NM_188056.2:c.2677 C > Tp. Arg893Cys) was identified, associated with arrhythmias, long QT, atrial fibrillation, and Brugada syndrome. Ancestral analysis revealed a predominant European component (43.9%), followed by Native American (35.7%) and African (20.4%) components. Conclusions: The participant presents atrial flutter and conduction disorders, despite lacking typical cardiovascular risk factors. The proband carries a SCN5A variant that has not been previously reported in Latin America and may be associated to her phenotype. The documented arginine-to-cysteine substitution at position 893 in the protein is crucial for various cellular functions. The subject’s mixed genetic composition highlights potential genetic contributors to atrial flutter, emphasizing the need for comprehensive genetic studies, particularly in mixed populations like Ecuadorians. This case underscores the importance of genetic analysis for personalized treatment and the significance of studying diverse genetic backgrounds in understanding cardiovascular diseases.
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Exploring Atrial Fibrillation: Understanding the Complex Relation Between Lifestyle and Genetic Factors
(Elmer Press, Inc., 2024-08)
Rafael Tamayo-Trujillo
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Elius Paz-Cruz
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CADENA ULLAURI, SANTIAGO ANDRE
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GUEVARA RAMIREZ, ALEXANDRA PATRICIA
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Viviana A. Ruiz-Pozo
Cardiovascular diseases (CVDs) are the leading cause of death worldwide across diverse ethnic groups. Among these, atrial fibrillation (AF) stands as one of the most prevalent types of arrhythmias and the primary cause of stroke. Risk factors associated with AF include alcohol consumption, aging, high blood pressure, hypertension, inflammation, and genetic factors. A family history of CVD could indicate an increased risk. Consequently, genetic, and genomic testing should be performed to identify the molecular etiology of CVDs and assess at-risk patients. It is important to note that CVDs are the results of the complex interplay of genes and environmental factors, including ethnicity. In this case, the proband’s clinic story includes a history of smoking abuse for 10 years (10 cigarettes per day), obesity, hypertension, and an associated familial history. These risk factors, along with genetic variants, could trigger the early onset of AF. In recent years, genetic and genomic studies have significantly advanced our understanding of CVD etiology, given that next-generation sequencing (NGS) allows for the identification of genetic variants that could contribute to these pathologies. Furthermore, NGS facilitates early diagnosis, personalized pharmacological approaches, and identification of novel biomarkers. Thus, NGS is a valuable tool in CVD management. However, such studies are limited in Ecuador, a low- and middle-income country. Several challenges contribute to this gap, encompassing economic, infrastructural, and educational obstacles. Notably, the cost of genetic and genomic studies may also pose a barrier, restricting access to a portion of the population. In this case report, we present a 56-year-old Ecuadorian woman, who has been diagnosed with AF; however, after performing NGS no disease-associated variants were found, despite having strong clinical signs and symptoms. In summary, this case report contributes valuable insights into the complex interplay between genetic and lifestyle factors in the development and management of AF. The case report aims to underscore the potential impact of genetic variants on disease risk, even when classified as variants of uncertain significance, and the importance of an integral approach to patient care that includes genetic screening, lifestyle interventions, and tailored pharmacological treatment.
Scopus© Citations 5
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Case report: Exploring Lynch Syndrome through genomic analysis in a mestizo Ecuadorian patient and his brother
(Frontiers Media SA, 2024-12-17)
GUEVARA RAMIREZ, ALEXANDRA PATRICIA
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RUIZ POZO, VIVIANA ALEJANDRA
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CADENA ULLAURI, SANTIAGO ANDRE
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Elius Paz-Cruz
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TAMAYO TRUJILLO, VICTOR RAFAEL
Lynch Syndrome (LS) is a hereditary disorder characterized by genetic mutations in DNA mismatch repair genes, affecting approximately 0.35% of the population. LS primarily increases the risk of colorectal cancer (CRC), as well as various other cancer types like endometrial, breast, and gastric cancers. Microsatellite instability, caused by MMR gene mutations, is a key feature of LS, impacting genes such as MLH1, MSH2, MSH6, and PMS2. Pathology tests studying microsatellite instability and immunohistochemical staining are used to diagnose LS. Furthermore, next-generation sequencing (NGS) allows for a thorough investigation of cancer susceptibility genes. This approach is crucial for identifying affected individuals and managing their care effectively. This study evaluated two siblings who harbored a mutation in the MLH1 gene associated with LS. The older brother was diagnosed with CRC at 24, while the younger brother remains asymptomatic at 7 years old. Genetic testing confirmed the presence of the MLH1 mutation in both siblings. Ancestry analysis showed a mix of African, European, and Native American heritage, common among Ecuadorians. Both siblings shared a family history of cancer, suggesting hereditary factors. Treatment involved surgery and chemotherapy for the older brother, emphasizing the importance of genetic testing for siblings with a cancer family history. NGS plays a pivotal role in identifying genetic mutations and guiding treatment decisions, demonstrating its significance in managing LS and other hereditary cancers.
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Genomic analysis of a novel pathogenic variant in the gene LMNA associated with cardiac laminopathies found in Ecuadorian siblings: A case report
(Frontiers Media SA, 2023-03-21)
GUEVARA RAMIREZ, ALEXANDRA PATRICIA
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CADENA ULLAURI, SANTIAGO ANDRE
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Rita Ibarra-Castillo
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José Luis Laso-Bayas
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Nieves Doménech
<jats:sec><jats:title>Introduction</jats:title><jats:p>Cardiac laminopathies are caused by mutations in the LMNA gene and include a wide range of clinical manifestations involving electrical and mechanical changes in cardiomyocytes. In Ecuador, cardiovascular diseases were the primary cause of death in 2019, accounting for 26.5% of total deaths. Cardiac laminopathy-associated mutations involve genes coding for structural proteins with functions related to heart development and physiology.</jats:p></jats:sec><jats:sec><jats:title>Family description</jats:title><jats:p>Two Ecuadorian siblings, self-identified as mestizos, were diagnosed with cardiac laminopathies and suffered embolic strokes. Moreover, by performing Next-Generation Sequencing, a pathogenic variant (NM_170707.3:c.1526del) was found in the gene LMNA.</jats:p></jats:sec><jats:sec><jats:title>Discussion and conclusion</jats:title><jats:p>Currently, genetic tests are an essential step for disease genetic counseling, including cardiovascular disease diagnosis. Identification of a genetic cause that may explain the risk of cardiac laminopathies in a family can help the post-test counseling and recommendations from the cardiologist. In the present report, a pathogenic variant ((NM_170707.3:c.1526del) has been identified in two Ecuadorian siblings with cardiac laminopathies. The LMNA gene codes for A-type laminar proteins that are associated with gene transcription regulation. Mutations in the LMNA gene cause laminopathies, disorders with diverse phenotypic manifestations. Moreover, understanding the molecular biology of the disease-causing mutations is essential in deciding the correct type of treatment.</jats:p></jats:sec>
Scopus© Citations 5
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Genetic diet interactions of ACE: the increased hypertension predisposition in the Latin American population
(Frontiers Media SA, 2023-10-26)
ZAMBRANO ESPINOSA, ANA KARINA
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CADENA ULLAURI, SANTIAGO ANDRE
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Adriana Alexandra Ibarra-Rodríguez
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Nieves Doménech
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GUEVARA RAMIREZ, ALEXANDRA PATRICIA
<jats:p>Hypertension is one of the primary risk factors associated with cardiovascular diseases (CVDs). It is a condition that affects people worldwide, and its prevalence is increasing due to several factors, such as lack of physical activity, population aging, and unhealthy diets. Notably, this increase has primarily occurred in low and middle-income countries (LMICs). In Latin America, approximately 40% of adults have been diagnosed with hypertension. Moreover, reports have shown that the Latin American genetic composition is highly diverse, and this genetic background can influence various biological processes, including disease predisposition and treatment effectiveness. Research has shown that Western dietary patterns, which include increased consumption of red meat, refined grains, sugar, and ultra-processed food, have spread across the globe, including Latin America, due to globalization processes. Furthermore, a higher than recommended sodium consumption, which has been associated with hypertension, has been identified across different regions, including Asia, Europe, America, Oceania, and Africa. In conclusion, hypertension is a multifactorial disease involving environmental and genetic factors. In Latin America, hypertension prevalence is increasing due to various factors, including age, the adoption of a “Westernized” diet, and potential genetic predisposition factors involving the <jats:italic>ACE</jats:italic> gene. Furthermore, identifying the genetic and molecular mechanisms of the disease, its association with diet, and how they interact is essential for the development of personalized treatments to increase its efficacy and reduce side effects.</jats:p>
Scopus© Citations 15
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Statins and their impact on epigenetic regulation: insights into disease
(Frontiers Media SA, 2025-07-17)
TAMAYO TRUJILLO, VICTOR RAFAEL
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GUEVARA RAMIREZ, ALEXANDRA PATRICIA
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CADENA ULLAURI, SANTIAGO ANDRE
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Viviana A. Ruiz Pozo
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PAZ CRUZ, ELIUS ANDRES
Statins have been primarily used for the management of low-density lipoprotein cholesterol and cardiovascular diseases However, in recent years, research has identified potential applications beyond cholesterol regulation. Statins exhibit pleiotropic effects, due to their ability to modulate gene expression via epigenetic mechanisms, including DNA methylation, histone acetylation, and microRNA regulation. Clinical studies have correlated these epigenetic changes with various pathological conditions, such as inflammation, atherosclerosis, cancer, diabetes, and autoimmune disorders. Despite encouraging findings, further research is required to fully understand the molecular pathways associated with the epigenetic actions of statins and disease pathogenesis. This review describes the potential role of statins as epigenetic modulators and their relevance in human disease management.
Scopus© Citations 5

GUEVARA RAMÍREZ, ALEXANDRA PATRICIA

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