Muscle carnitine palmitoyltransferase deficiency

This code identifies a specific metabolic disorder characterized by the body's inability to properly break down long-chain fatty acids for energy, primarily affecting muscle tissue. It results from a deficiency in carnitine palmitoyltransferase II (CPT II), an enzyme crucial for transporting fatty acids into mitochondria. Patients typically experience recurrent episodes of muscle pain, weakness, and rhabdomyolysis, often triggered by prolonged exercise, fasting, or illness.

Assign this code for patients diagnosed with muscle CPT II deficiency based on clinical presentation, enzyme assays, and/or genetic testing. Documentation should clearly indicate the specific type of carnitine palmitoyltransferase deficiency as affecting the muscle. This code is appropriate when the patient presents with symptoms directly attributable to this metabolic defect.

• Differentiate from other carnitine deficiencies; ensure documentation specifies "muscle" and "palmitoyltransferase."
• Do not confuse with systemic carnitine deficiency (E71.310) or other unspecified carnitine transport disorders.
• Sequence as a primary diagnosis when it is the reason for the encounter, or as a secondary diagnosis if it's an underlying condition impacting treatment.