What are the key clinical features to consider when diagnosing Duchenne Muscular Dystrophy in a child?

Key clinical features to consider when diagnosing Duchenne Muscular Dystrophy (DMD) in a child include:

• Progressive proximal muscle weakness, typically presenting in early childhood, often between ages 2 and 5 years, with difficulty in activities such as running, climbing stairs, or rising from the floor (Gowers' sign).
• Delayed motor milestones and frequent falls are common early indicators.
• Calf pseudohypertrophy due to muscle tissue being replaced by fat and connective tissue is a characteristic physical finding.
• Enlarged calf muscles and lumbar lordosis may be observed on examination.
• Elevated serum creatine kinase (CK) levels are a biochemical hallmark, often markedly raised even before clinical symptoms become apparent.
• Cardiac involvement may be present early, with electrocardiographic abnormalities such as conduction defects and arrhythmias, necessitating cardiac evaluation as part of diagnosis and ongoing management.
• Respiratory muscle weakness can develop as the disease progresses, although this is more relevant in later stages.
• Cognitive impairment or learning difficulties may be present in some children, reflecting the multisystem nature of the disease.

These features combined with a family history of DMD or a known dystrophin gene mutation support the diagnosis. Genetic testing confirming dystrophin gene mutations is definitive. Early recognition of these clinical signs is critical for timely referral and management NICE NG127 Yiu & Kornberg 2008Annexstad et al. 2014Tang et al. 2022.