Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
Browse
Search Results
- Analysis of the efficacy of the hexanucleotide repeat expansion of the C9orf72 gene as a diagnostic biomarker for Amyotrophic Lateral Sclerosis in Mexican patients(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06-13) Villalobos Loredo, Manuel Alejandro; Díaz Durán, Raquel Cuevas; emimmayorquin; Martínez Ledesma, Juan Emmanuel; Hernández Pérez, Jesús; School of Engineering and Sciences; Campus MonterreyAmyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disorder with significant genetic underpinnings, including the hexanucleotide repeat expansion (HRE) in the C9orf72 gene, a leading genetic cause of ALS in European populations. Despite its global relevance, the prevalence and diagnostic utility of C9orf72 HREs in Mexican ALS patients remain poorly characterized due to limited research in Latin America. This study aimed to evaluate the efficacy of C9orf72 HREs as a diagnostic biomarker for ALS in Mexican patients, employing repeat-primed PCR (RP-PCR) and capillary electrophoresis (CE) to analyze repeat lengths in 47 sporadic ALS patients and 7 healthy controls. Results revealed distinct repeat distributions, with the most common alleles being 2, 5, and 7 units in both cohorts. Notably, one patient carried a pathogenic expansion (>145 repeats), marking the first detection and successful sizing of C9orf72 HRE for ALS in Mexico. Statistical analyses demonstrated significant differences in allele distributions between patients and controls ( 𝒑<𝟎.𝟎𝟓), supporting the association of HREs with ALS pathogenesis. However, no correlation was found between repeat length and disease severity (𝑹𝟐=𝟎.𝟎𝟎𝟓), suggesting that expansion size may not predict clinical progression. This study successfully established a robust protocol for C9orf72 HRE detection in a Mexican cohort, addressing a critical gap in regional ALS research. The findings highlight the importance of population specific studies to refine diagnostic criteria and improve genetic counseling. While the low frequency of pathogenic expansions in this cohort suggests alternative genetic or environmental factors may dominate ALS etiology in Mexico, the demonstrated feasibility of RP-PCR and capillary electrophoresis paves the way for broader implementation of genetic testing in resource-limited settings. Future studies with larger cohorts are needed to validate these findings and explore their implications for personalized medicine in Latin America.
- Digital PCR analysis of ALS plasma miRNA biomarkers: towards analytical consistency and pathogenic relevance(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06-10) Muñoz Arteaga, José Antonio; Díaz Durán, Raquel Cuevas; emipsanchez; Paul, Sujay; Pérez Martínez, Leonor; Fajardo Ramírez, Oscar Raúl; Escuela de Medicina y Ciencias de la Salud; Campus MonterreyAmyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease marked by motor neuron degeneration without properly standardized molecular biomarkers for early diagnosis or disease monitoring. Diagnosis remains primarily clinical, often involving lengthy exclusion processes and significant delays, highlighting the need for minimally invasive, accessible, and disease-specific molecular tools. Circulating microRNAs (miRNAs) are promising biomarker candidates due to their stability in plasma/serum and roles in gene regulation. This study aimed to quantify the expression of selected ALS-associated plasma miRNAs using digital PCR (dPCR) and compare them against those in healthy controls to validate their efficacy as early ALS biomarkers. Plasma samples were collected from eight ALS patients and four age-and-sex-matched healthy controls. Four candidate target miRNAs (hsa-miR-93-5p, hsa-miR-181a-5p, hsa-miR-206, hsa-miR-7111-3p) and one endogenous control (hsa-miR-191-5p) were selected via systematic review. Total miRNA concentration did not significantly differ between ALS patients and controls, suggesting global miRNA levels are not altered in ALS. Hsa-miR-206 was consistently upregulated across all analysis strategies, supporting its role as a robust biomarker. Hsa-miR-93-5p also showed significant differential expression, though results were dependent on normalization approach. Correlation analysis with ALS Functional Rating Scale-Revised (ALSFRS-R) scores revealed moderate but non-significant trends for both miRNAs. Target prediction analysis linked both miRNAs to ALS-associated genes, suggesting potential involvement in disease pathways. The study concludes that miR-206 is a promising candidate for clinical translation as a diagnostic and prognostic biomarker. It also emphasizes the importance of methodological standardization in miRNA research to ensure reproducibility and clinical applicability. Further validation in larger cohorts is necessary to confirm these findings.