Pelizaeus-Merzbacher disease

This code identifies Pelizaeus-Merzbacher disease (PMD), a rare, X-linked leukodystrophy characterized by abnormal development of myelin in the central nervous system. It results in progressive neurological deterioration, including nystagmus, ataxia, spasticity, and developmental delay. The severity and onset of symptoms vary depending on the specific genetic mutation.

Use this code for patients diagnosed with Pelizaeus-Merzbacher disease, confirmed by genetic testing or characteristic clinical presentation and imaging findings (e.g., MRI showing diffuse hypomyelination). Documentation should clearly state the diagnosis of PMD, often with details regarding the specific type or genetic mutation if known.

• Ensure documentation specifies "Pelizaeus-Merzbacher disease" and not a general leukodystrophy.
• Consider additional codes for associated neurological manifestations such as nystagmus (H55.0), ataxia (R27.0), or spasticity (R25.2).
• This code is highly specific; avoid using it for other demyelinating conditions unless PMD is explicitly diagnosed.