Medicine (Baltimore). 2026 Jan 16;105(3):e46993. doi: 10.1097/MD.0000000000046993.
ABSTRACT
RATIONALE: Danon disease (DD) is an X-linked lysosomal storage disorder caused by LAMP2 variants, with males presenting more severe phenotypes. However, evidence for genotype-phenotype correlation remains limited. This study reports 2 male DD patients with distinct LAMP2 mutations to clarify mutation-specific prognostic differences.
PATIENT CONCERNS: A 15-year-old male: chest tightness and palpitations, creatine kinase (CK) 3867 U/L, and hypertrophic cardiomyopathy. A 12-year-old male: exertional dyspnea and syncope, left ventricular ejection fraction 36%, left ventricular thrombus, and CK 5210 U/L.
DIAGNOSES: Both were diagnosed with DD via genetic testing: the 15-year-old had a LAMP2 IVS6 + 1G > T splice mutation, and the 12-year-old carried a LAMP2 exon 1 deletion.
INTERVENTIONS: The 15-year-old underwent heart transplantation followed by immunosuppressive therapy. The 12-year-old received only symptomatic treatment without transplantation.
OUTCOMES: The 15-year-old had normal cardiac function and normalized CK levels during 24-month posttransplant follow-up. The 12-year-old died of heart failure 8 months after diagnosis.
LESSONS: LAMP2 mutation types correlate with DD severity. Heart transplantation improves prognosis in severe cases, emphasizing the importance of early diagnosis and intervention.
PMID:41560058 | DOI:10.1097/MD.0000000000046993