In a suspected case of Duchenne muscular dystrophy, when is it appropriate to check creatine kinase levels?

In a suspected case of Duchenne muscular dystrophy (DMD), checking creatine kinase (CK) levels is appropriate when assessing for early signs in children, particularly those exhibiting developmental delays or motor difficulties. A 15-month-old male who is unable to stand without support is a prime candidate for testing because this milestone is critical in the evaluation of motor development.

Duchenne muscular dystrophy typically manifests in early childhood, and delayed milestones, such as standing or walking, can indicate underlying muscular issues. Elevated CK levels are commonly found in individuals with muscular dystrophy, serving as a key indicator of muscle damage. Therefore, evaluating CK levels in a child who is significantly delayed in reaching motor milestones can help guide further diagnostic steps.

Other scenarios, such as presenting with a fever, being older than 6 years, or having muscle aches, do not directly correlate with the urgency of testing for DMD. Individuals presenting with these issues may not exhibit the specific developmental concerns necessary to prioritize CK level testing related to DMD suspicion. Thus, the choice involving the 15-month-old male reflects the importance of timely investigation in the context of developmental milestones.