Noninfectious endocarditis as a novel cardiac manifestation of glycogen storage disease type IV: a case report.

Background: Glycogen storage disease type IV (GSD IV), Andersen disease, is a rare autosomal recessive disorder of glycogen metabolism typically associated with liver failure and cardiomyopathy. Isolated non-infectious cardiac valvular disease as a sequela of GSD IV has not been previously reported in this population. We aim to describe the first reported case of non-infectious endocarditis as a novel cardiac manifestation in a patient with GSD IV. Case Description: We report the case of a 16-year-old male with GSD IV, status post liver transplant in infancy, who presented with fever, fatigue, and cough. He was found to have new-onset mitral valve disease and, over 6 weeks, developed progressive polyvalvular pathology affecting the mitral, aortic, tricuspid, and pulmonary valves. Despite broad-spectrum antibiotics, his condition worsened and necessitated surgical mitral valve replacement, aortic valve reconstruction, and tricuspid valve repair. An extensive infectious and rheumatologic work-up-including serial blood cultures, cell-free deoxyribonucleic acid (DNA) testing (Karius Conclusions: This is the first report of non-infectious endocarditis, also known as Libman-Sacks endocarditis, in a patient with GSD IV as a primary manifestation of their underlying metabolic disorder, representing a novel cardiac manifestation of the disease. In patients with GSD IV who develop valvular lesions and have a negative infectious work-up, clinicians should consider noninfectious endocarditis as a progression of their genetic disease. Regular cardiac surveillance may be warranted in this population to identify valvular involvement early.