Niemann-Pick disease type A/B

This code identifies Niemann-Pick disease type A/B, a rare, inherited metabolic disorder characterized by the accumulation of sphingomyelin in various organs due to a deficiency in the acid sphingomyelinase enzyme. Type A is a severe infantile neurodegenerative form, while type B is a more heterogeneous, chronic visceral form with variable neurological involvement.

Use this code for patients diagnosed with either Niemann-Pick disease type A or type B, confirmed through genetic testing or enzyme activity assays. Documentation should clearly specify the diagnosis of Niemann-Pick disease and, if possible, differentiate between type A and B based on clinical presentation and diagnostic findings.

• Ensure documentation specifies "type A" or "type B" to support this specific code, as other Niemann-Pick types exist.
• Do not confuse with E75.240 (Niemann-Pick disease type C), which is a distinct genetic disorder with different underlying pathophysiology.
• Code any associated manifestations or complications, such as hepatosplenomegaly, interstitial lung disease, or neurological deficits, as secondary diagnoses.