Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 64 9 2026 08 19 612 620 Azhar Y. Dhannoon Iraq 2026 04 26 2026 05 10 Abstract Dilated Cardiomyopathy is the major cause congestive heart failure and sudden cardiac death. It is a type of cardiomyopathy; characterized by ventricular dilatation, wall thinning and systolic dysfunction. TTN gene is implicated in DCM and encodes for giant titin protein. This study explores the association between TTN gene expression with some types of non-coding RNAs in DCM patients. Methodology: The study design was divided into three groups: control, male and female group, each group involve (20) individuals (healthy and patients). Detecting the levels gene expression for TTN gene and miRNA200a, lncRNA FOXD2-AS1 and snoRNA-42 genes via qRT-PCR technique. Results: TTN gene expression was significantly elevated in both male and female DCM patients compared with controls (P < 0.001). Furthermore, miR-200a and snoRNA-42 levels were also significantly increased in DCM patients particularly in females. In contrast, lncRNA FOXD2-AS1 was significantly decreased in both sex of DCM patients. ROC curve analysis for TTN gene demonstrated high diagnostic performance, sensitivity and specificity with (p = 0.0022), supporting TTN as a reliable molecular biomarker for DCM. Furthermore, miR-200a showed a potent biomarker for DCM, particularly in females. The observed p-values (0.0275 in males and 0.0022 in females) indicating its superior efficiency in clinical differentiation, and further support its potential as a sex-specific biomarker. Pearson correlation analysis detected a negative correlation between miR-200a and TTN mRNA in both males and females, negative correlations were also observed between miR-200a and titin protein levels. In contrast, TTN gene expression and titin protein levels showed a positive correlation, indicating transcription-driven increases in titin level. https://acta.tums.ac.ir/index.php/acta/article/view/12095 https://acta.tums.ac.ir/index.php/acta/article/download/12095/6106