GUEVARA RAMÍREZ, ALEXANDRA PATRICIA
Preferred name
GUEVARA RAMÍREZ, ALEXANDRA PATRICIA
Main Affiliation
CIGG - Centro de Investigación Genética y Genómica
Web Site
ORCID
0000-0002-4829-3653
Scopus Author ID
57195725827
75 results
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Item type:Publication, Genetic variation of high-altitude Ecuadorian population using autosomal STR markers(Elsevier BV, 2019-12); Scopus© Citations 1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Exploring Atrial Fibrillation: Understanding the Complex Relation Between Lifestyle and Genetic Factors(Elmer Press, Inc., 2024-08); ; Viviana A. Ruiz-PozoCardiovascular 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 6 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Spectrum and Clinical Interpretation of TTN Variants in Ecuadorian Patients with Heart Disease: Insights into VUS and Likely Pathogenic VariantsThis 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.Scopus© Citations 4 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Next-Generation sequencing in a Native American patient with sea-blue histiocytosis: A case report and genomic analysis(Medwave Estudios Limitada, 2025-08-08); ; ; This study presents a case of a 25-year-old Native American woman from Otavalo, Ecuador, diagnosed with sea-blue histiocytosis and myelodysplastic syndrome. Bone marrow aspiration revealed sea-blue histiocytes, and next-generation sequencing identified a likely pathogenic stop-gain mutation in the gene, associated with myelodysplastic syndrome. Additionally, variants of uncertain significance were found in the and genes. Ancestral analysis showed a predominantly Native American composition, suggesting a potential genetic predisposition specific to Andean communities. The report underscores the importance of understanding genetic and ancestral backgrounds in diagnosing and managing hematological disorders. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The genomic bases of atrial fibrillation in an Ecuadorian patient: a case report(Frontiers Media SA, 2025-06-23); ; ; Atrial fibrillation (AF) is one of the most globally prevalent arrhythmias with multifactorial factors, including environmental and genetic predisposition influences. The present case report describes a 30-year-old Ecuadorian mestizo male diagnosed with persistent AF with an history of hyperthyroidism, later progressing to hypothyroidism post-radioactive iodine therapy. Genomic test identified variants of uncertain significance in the TTN, MYH11, and RAF1 genes, which are associated with cardiovascular diseases but not directly linked to AF. The interplay between thyrotoxicosis and genetic predispositions is discussed as a potential mechanism underlying AF development. This report emphasizes the need for genomic screening and personalized strategies in populations like Ecuador with complex genetic and environmental backgrounds. 2025 Tamayo-Trujillo, Guevara-Ramirez, Meza-Chico, Cadena-Ullauri, Ruiz-Pozo, Paz-Cruz, Laso-Bayas, Ibarra-Castillo and Zambrano.Scopus© Citations 92 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Salivary MicroRNAs for Early Detection of Head and Neck Squamous Cell Carcinoma: A Case-Control Study in the High Altitude Mestizo Ecuadorian Population(Hindawi Limited, 2018-11-21)Scopus© Citations 54 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Evaluation of ancestral membership proportions and genotype distribution in the perception of Umami taste in Ecuadorian mestizos(Elsevier BV, 2017-12); Scopus© Citations 1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, The Non-Coding rs5945619 Variant at Xp11.22 and Its Putative Regulatory Effects on Nearby Genes in Ecuadorian Mestizo Women with Breast Cancer: A Case Series and In Silico Cis-eQTL Analysis(MDPI AG, 2026-08-07); ; ; ; Ruiz-Pozo, Viviana A. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Novel nonsense mutation in the TCOF1 gene associated with treacher collins syndrome: A case report(SAGE Publications, 2025-04); ; ; ; Treacher Collins Syndrome (TCS) is a congenital disorder characterized by craniofacial malformations. In this case, a novel likely pathogenic nonsense variant, in the TCOF1 gene, associated with TCS, was reported. Genetic analysis was performed on an Ecuadorian participant (Subject A) and his mother (Subject B), both of whom exhibited characteristic features of TCS. Next-generation sequencing (NGS) identified a single nucleotide variant (c.4423A > T) in exon 25 of the TCOF1 gene, resulting in a premature stop codon (p.(Lys1475Ter)) and a truncated treacle protein. The likely pathogenic variant presented in Subjects A and B could alter critical functions of the protein, contributing to the craniofacial malformations of the subjects. The variant informed in this case report contributes to the knowledge of TCOF1 gene variants associated with TCS and highlights the importance of genomic screening for accurate diagnosis and improved clinical management in patients and families. © The Author(s) 2025. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Molecular Mechanisms and Therapeutic Perspectives of Gut Microbiota, Autophagy, and Apoptosis in Cholangiocarcinoma PathophysiologyCholangiocarcinoma (CCA) is an aggressive malignancy of the biliary tract with rising global incidence and limited treatment options. Its pathogenesis involves a complex interplay of genetic mutations, epigenetic dysregulation, inflammatory signaling, and environmental influences. Emerging evidence highlights the pivotal role of the gut–liver axis and microbiota dysbiosis in shaping biliary homeostasis and disease progression. Alterations in microbial composition disrupt apoptosis and autophagy, two key processes regulating cell survival and death, thereby contributing to tumorigenesis, metastasis, and therapy resistance. Specific taxa, including Enterococcus, Escherichia coli, Pseudomonas, Bifidobacterium, and Bacillus, demonstrate strain-dependent effects, acting either as tumor promoters through genotoxic metabolites and immune evasion or as potential tumor suppressors by inducing apoptosis and immune activation. These findings underscore the context-dependent roles of microbiota in CCA biology. Importantly, microbiota modulation offers novel therapeutic opportunities. Dietary interventions such as probiotics, prebiotics, and nutritional strategies, alongside innovative microbiome-targeted therapies, hold promise for restoring microbial balance, enhancing antitumor immunity, and improving patient outcomes. This review integrates current molecular and microbiological evidence to propose the gut microbiota as both a biomarker and a therapeutic target in CCA, opening avenues for precision medicine approaches in hepatobiliary oncologyScopus© Citations 1