S-080 | Assessment of differentially expressed miRNAs as potential diagnostic and prognostic biomarkers for evaluating the presence and severity of clinical manifestations in girls with Rett syndrome

Disorders of the Nervous System
Author: María Belén Cardillo | Email: belencardillo@gmail.com

M. Belén Cardillo^1°, Patricia A. Paloscia^2°, Bruno G. Berardino^1°,  Eduardo T. Cánepa^1°, , , ,  , ,

^1° Laboratorio de Neuroepigenética y Adversidades Tempranas – Departamento de Química Biológica – Facultad de Ciencias Exactas y Naturales – Universidad de Buenos Aires / Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
^2° Departamento de Química Biológica – Facultad de Ciencias Exactas y Naturales – Universidad de Buenos Aires / Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN)

Rett syndrome (RTT) is a severe neurological disorder primarily affecting girls, caused by mutations in the MeCP2 gene. The disease is characterized by developmental regression after normal growth, with symptoms such as loss of speech and motor skills, stereotypic hand movements, and seizures. Due to the complexity and cost of clinical and genetic tests, identifying accessible and effective biomarkers for diagnosis is crucial. This study evaluated differentially expressed miRNAs in girls with RTT as potential diagnostic and prognostic biomarkers for the severity of clinical manifestations. Small RNAs were extracted from blood samples of RTT-diagnosed girls and control subjects without neurodevelopmental disorders, and expression of selected miRNAs was measured by RT-qPCR. Additionally, miRNA expression was analyzed across three age groups corresponding to disease progression. No significant differences were observed in miRNA expression between the RTT and control groups, and attempts to correlate miRNA expression with clinical severity yielded no significant results. A ROC curve analysis for miR-22-3p showed an area under the curve (AUC) of 0.65, indicating its predictive capacity, with a cut-off point of 0.8, specificity of 1, and sensitivity of 0.42. These results highlight the need to broaden the miRNAs studied and to increase the study participants, essential steps for improving it’s reliability as biomarkers for RTT diagnosis. Both aspects are currently in progress.