DMD Gene Variants and Cardiac Dysfunction in Young Males With Dystrophinopathies

Inclusion Criteria: * Male sex * Age between 2 and 24 years at the time of enrollment * Genetically confirmed dystrophinopathy with a pathogenic or likely pathogenic variant in the DMD gene * Genetic confirmation based on at least one validated method, including MLPA, NGS, Sanger sequencing, array-CGH, or qPCR * Written informed consent from parents or legal guardians and, where applicable, consent from the participant Exclusion Criteria: * Absence of a genetically confirmed diagnosis of dystrophinopathy, including: * diagnosis based solely on muscle biopsy without molecular confirmation of a pathogenic or likely pathogenic DMD gene variant * absence of a confirmed pathogenic variant in the DMD gene, even if maternal carrier status has been identified, unless repeat genetic testing confirms a pathogenic variant in the participant * Presence of congenital heart disease or other genetic disorders causing primary cardiomyopathy * Presence of other neuromuscular disorders * Female carriers, including both manifesting and asymptomatic carriers * Comorbidities that may independently affect cardiac function, such as severe arterial hypertension, diabetes mellitus, or chronic kidney disease