Danon disease: Two case reports and literature review

Area of Science:

• Genetics
• Cardiology
• Rare Diseases

Background:

• Danon disease (DD) is an X-linked lysosomal storage disorder caused by LAMP2 gene variants.
• Males typically exhibit more severe phenotypes, but genotype-phenotype correlations are not well-established.
• Limited data exists on how specific LAMP2 mutations influence disease prognosis.

Purpose of the Study:

• To investigate the correlation between distinct LAMP2 mutations and clinical outcomes in male Danon disease patients.
• To clarify mutation-specific prognostic differences in Danon disease.
• To evaluate the impact of therapeutic interventions, such as heart transplantation, on disease progression.

Main Methods:

• Case report of two male patients diagnosed with Danon disease via genetic testing.
• Detailed clinical presentation, including cardiac function and creatine kinase (CK) levels, was recorded.
• Treatment strategies, including heart transplantation and symptomatic management, were compared.

Main Results:

• Patient 1 (15-year-old) with a LAMP2 IVS6+1G>T splice mutation underwent heart transplantation and showed normalized cardiac function and CK levels post-surgery.
• Patient 2 (12-year-old) with a LAMP2 exon 1 deletion received only symptomatic treatment and died of heart failure within 8 months.
• Significant difference in outcomes based on mutation type and intervention received.

Conclusions:

• Specific LAMP2 mutation types are associated with varying severity in Danon disease.
• Heart transplantation can significantly improve prognosis in male patients with severe Danon disease.
• Early diagnosis and timely intervention are crucial for managing Danon disease effectively.