The case involved a 22-year-old uninsured male who presented in cardiogenic shock due to a dilated cardiomyopathy and required temporary mechanical support. The patient’s thin body habitus combined with bilateral ptosis and subtle upper-extremity weakness proved crucial in raising suspicion for a mitochondrial myopathy. A subsequent muscle biopsy confirmed the presence of a mitochondrial myopathy known as Kearns-Sayre syndrome (KSS). Notably, KSS is not associated with a dilated cardiomyopathy, and concurrent genetic testing identified a pathogenic mutation in the plakophilin-2 protein (PKP2) gene.
The PKP2 protein is crucial in the structure of desmosomes, proteins that attach two adjacent myocytes to one another. Pathogenic mutations in this protein can result in arrhythmogenic cardiomyopathy (ARVC). Ultimately, the patient obtained insurance and underwent an uncomplicated heart transplant. His native heart pathology revealed fibrofatty myocyte replacement, confirming a diagnosis of ARVC, undoubtedly related to the PKP2 mutations.