Becker Muscular Dystrophy: Diagnosis, Initial Management, and Comparison with Duchenne Dystrophy

Becker muscular dystrophy (BMD) is a hereditary neuromuscular disease that primarily affects males, with an incidence of approximately 1 in 18,000 male births. This condition is caused by mutations in the dystrophin gene located on the X chromosome, resulting in reduced or defective production of this essential protein for muscle membrane stability. Unlike Duchenne muscular dystrophy (DMD), BMD presents a milder clinical course and slower progression, making its differentiation crucial for appropriate management.

Diagnosis and Initial Management

The diagnosis of BMD is based on a combination of clinical findings, laboratory tests, and genetic studies. A muscle biopsy can reveal characteristic changes, although genetic analysis is the gold standard for confirming the mutation in the dystrophin gene. Electromyography (EMG) remains a valuable tool in the initial evaluation of neuromuscular disorders, helping to differentiate between myopathic and neuropathic lesions.

Initial management of BMD requires a multidisciplinary approach that includes the evaluation and monitoring of neurological, respiratory, cardiac, and orthopedic complications. French guidelines recommend regular monitoring of cardiac function, as cardiomyopathy is a common complication in these patients. Additionally, cardiorespiratory evaluation is essential for early detection and management of any functional deterioration.

Differentiation from Duchenne

The comparison with Duchenne is fundamental for establishing an accurate diagnosis. Although both conditions share the same X-linked inheritance pattern, BMD is characterized by a later onset of symptoms and slower progression. Creatine kinase (CK) levels are typically elevated in both conditions, but gamma-glutamyl transferase (GGT) may be useful in differentiating muscle damage from liver damage, especially in the context of potentially hepatotoxic treatments.

Conclusions

Becker muscular dystrophy is a complex disease that requires accurate diagnosis and comprehensive management to improve the quality of life for patients. Proper differentiation from DMD is crucial to avoid unnecessary treatments and optimize clinical management. Interdisciplinary collaboration and regular follow-up are essential to address associated complications and provide optimal care for these patients.

Referencias

• [1] Usefulness of electromyography in diagnostics of the neuro-muscular diseases.
• [2] Fidelity of gamma-glutamyl transferase (GGT) in differentiating skeletal muscle from liver damage.
• [3] Diagnosis and management of Becker muscular dystrophy: the French guidelines.

Created 13/1/2025