Lysosome-associated membrane protein 2 [LAMP2] deficiency

This code represents Danon disease, a rare X-linked lysosomal storage disorder characterized by a deficiency in the lysosome-associated membrane protein 2 (LAMP2). The deficiency leads to the accumulation of autophagic vacuoles in various tissues, primarily affecting the heart, skeletal muscle, and intellect. Patients typically present with hypertrophic cardiomyopathy, myopathy, and intellectual disability.

Use this code when documentation confirms a diagnosis of Danon disease, often supported by genetic testing identifying a pathogenic variant in the LAMP2 gene. It is appropriate for patients exhibiting the characteristic triad of cardiomyopathy, myopathy, and intellectual disability, or those with a confirmed genetic diagnosis even if all symptoms are not yet fully manifest.

• Ensure documentation specifies a confirmed LAMP2 deficiency or Danon disease; avoid using for general lysosomal storage disorders without specific genetic confirmation.
• Code any associated manifestations, such as hypertrophic cardiomyopathy (I42.2), intellectual disabilities (F70-F79), or muscle weakness (M62.81), as secondary diagnoses.
• This code is highly specific; do not confuse with other lysosomal storage disorders like Pompe disease (E74.02) or Fabry disease (E75.21).