DMD is caused by variants in the DMD gene and follows an X-linked recessive inheritance pattern. Males who inherit one altered copy are typically affected, while females who carry one altered copy on one X chromosome may experience mild symptoms due to variable X-inactivation. Each son of a carrier female has a 50% chance of being affected; each daughter has a 50% chance of being a carrier. Female carriers should discuss cardiac monitoring and other health considerations with their healthcare provider. Genetic counseling is strongly recommended for all families.

Diagnosis is confirmed through molecular genetic testing identifying pathogenic variants in the DMD gene, including sequence analysis and deletion or duplication testing. Elevated serum creatine kinase concentration is a characteristic biomarker frequently detected before or alongside genetic testing. Clinical evaluation includes assessment of motor development, muscle strength, and family history. Because many of these features can overlap with other neuromuscular conditions, molecular genetic testing is essential to confirm the diagnosis and distinguish DMD from similar presentations.

Several FDA-approved therapies are available for DMD. Corticosteroid-based treatments, including deflazacort (EMFLAZA) and vamorolone (AGAMREE), help maintain muscle function and slow progression and are foundational for most patients. Givinostat (DUVYZAT) is also FDA-approved. Exon-skipping therapy casimersen (AMONDYS 45) targets a specific genetic mutation subset. The gene therapy delandistrogene moxeparvovec-rokl (ELEVIDYS) is FDA-approved with specific eligibility criteria. Multidisciplinary care involving neurology, cardiology, pulmonology, and physical therapy is essential. Patients should discuss options with their care team to determine which therapies suit their individual situation.

The course of DMD is variable and depends on individual factors including the specific genetic variant, access to specialized care, and response to treatment. Progressive muscle weakness typically leads to loss of independent ambulation over time, followed by increasing respiratory and cardiac involvement. With current standards of care, including corticosteroids and respiratory support, outcomes have improved for many individuals. Cardiac and pulmonary complications are important long-term considerations. Outcomes continue to evolve as new therapies become available, and individuals diagnosed today may experience a different trajectory than those diagnosed in earlier decades.

DMD is an active area of research with numerous ongoing clinical trials investigating new treatment approaches, including novel gene therapies, exon-skipping strategies, and other investigational agents. This breadth of research activity reflects the significant scientific investment in improving outcomes for affected individuals and families. Individuals interested in participating in clinical trials can search ClinicalTrials.gov or speak with their care team about eligibility and available studies.