Danon disease synonyms

Danon disease is a rare, multisystem X-linked genetic disorder primarily characterized by cardiomyopathy, skeletal myopathy, and intellectual disability. While formally recognized as Danon disease, it is sometimes referred to as glycogen storage disease type IIb or lysosomal glycogen storage disease with normal acid maltase activity in older or specialized clinical literature.

What are the historical and alternative names for Danon disease?

In medical literature, you may encounter several terms used to describe Danon disease. Historically, because the condition involves the accumulation of glycogen within lysosomes, it was classified under the umbrella of glycogen storage diseases. Specifically, it was known as glycogen storage disease type IIb. Researchers also used the descriptive term "lysosomal glycogen storage disease with normal acid maltase activity" to differentiate it from Pompe disease, which also affects glycogen storage but involves a deficiency in acid alpha-glucosidase. Because Danon disease is caused by mutations in the LAMP2 gene, it is also occasionally referred to in genetic databases as LAMP2 deficiency.

Why does Danon disease have multiple names?

The variety of names for Danon disease stems from the evolution of clinical understanding. Before the discovery of the underlying genetic cause in 2000, physicians classified the condition based on how it appeared under a microscope (histology) or how the body processed sugar (metabolism). As genetic testing became the standard for diagnosis, the medical community moved toward using the eponym "Danon disease," named after Dr. Minu Danon, who first described the condition in 1981. This transition helps avoid confusion with other metabolic myopathies that share similar outward symptoms but have different genetic origins.

What is the official classification of Danon disease?

Standardized medical systems have assigned specific identifiers to ensure consistency in medical records and research. Using these codes can be helpful when communicating with specialists or insurance providers:

• OMIM (Online Mendelian Inheritance in Man): #300257


• Orphanet: ORPHA221 (linked to LAMP2 deficiency)


• ICD-10/11: Often classified under codes for "Other specified disorders of lysosomal metabolism" or "Cardiomyopathy associated with other systemic diseases."

Which name is preferred by medical professionals?

Today, the term Danon disease is the preferred nomenclature in clinical practice and scientific research. Using this name ensures that the specific X-linked inheritance pattern and the characteristic triad of symptoms—cardiomyopathy, myopathy, and cognitive impairment—are immediately recognized by cardiologists, neurologists, and geneticists. If you are reviewing older medical records, you may see the term "glycogen storage disease type IIb," but your current care team will likely refer to your condition as Danon disease to reflect the most accurate diagnostic understanding.

Next steps for patients and families

• Consult with a cardiologist or a neuromuscular specialist who has experience with Danon disease.


• Request a genetic consultation to discuss the LAMP2 gene mutation and its implications for family members.


• Connect with the 4 community members registered on DiseaseMaps.org to share experiences and coping strategies.


• Ask your physician about participating in clinical registries to help improve the understanding of this rare condition.

Medical disclaimer: This information is for educational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Danon disease.


• Orphanet: LAMP2 deficiency (ORPHA221).


• Online Mendelian Inheritance in Man (OMIM): Entry #300257 (Danon Disease).


• Danon Disease Foundation: Resources for patients and families.