Which test is most commonly used in the initial diagnostic assessment of Duchenne muscular dystrophy?

• A. CK Level
• B. MRI Brain
• C. Bone Scan
• D. Echocardiogram

Answer: (A)

Duchenne muscular dystrophy causes rapid breakdown of skeletal muscle, leading to leakage of muscle enzymes into the blood. The serum creatine kinase level becomes markedly elevated early in the disease, often well above normal, so this test is the most sensitive and practical initial screen when DMD is suspected. A high CK prompts confirmatory genetic testing for dystrophin mutations and appropriate referral. Other options don’t fit the initial diagnostic role: MRI of the brain isn’t used to diagnose a muscle dystrophy, bone scans focus on bone metabolism, and echocardiograms assess heart function rather than establishing a muscular dystrophy diagnosis. The elevated CK reflects muscle membrane fragility and ongoing muscle damage, which is the hallmark that guides further evaluation.