When ‘Liver Enzymes’ Are Not Hepatic: Late-Onset Pompe Disease

Elevated liver function tests are commonly attributed to hepatic disease but may reflect extrahepatic pathology. We describe the case of an 18-year-old athletic woman with a 2-year history of elevated aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine kinase (CK) levels, initially investigated extensively for hepatic causes. Despite normal liver imaging and biopsy, ongoing abnormalities prompted metabolic evaluation, leading to the diagnosis of late-onset Pompe disease. This case highlights the diagnostic challenges of rare metabolic myopathies, the importance of recognising muscle-derived aminotransferase elevation and the need for broad diagnostic consideration when standard investigations are unrevealing.