A challenging etiology of myopathy: The late-onset Pompe disease

Pompe disease is a rare metabolic disorder that is characterized by the deficiency of the acid alpha-glucosidase. As a result, glycogen accumulates in several tissues including motor neurons, skeletal, cardiac, and smooth muscles. The course of the disease varies according to the type of mutations, and the clinical phenotype can be affected by the enzyme levels. Late-onset Pompe disease (LOPD) is a challenging issue for clinicians as it has a milder phenotype with later onset of symptoms and slower disease progression. One of the most important differentials in the diagnosis of LOPD is inflammatory myositis as both diseases have some common clinical and laboratory features. Herein, we presented a 30-year-old female patient initially diagnosed as polymyositis and treated with immunosuppressive therapy without a benefit on her symptoms and later diagnosed as LOPD.

Automated summary

Pompe disease is a rare metabolic disorder characterized by deficiency of acid alpha-glucosidase, leading to glycogen accumulation in various tissues. Late-onset Pompe disease (LOPD) poses challenges for clinicians due to its milder phenotype and slower progression. Differential diagnosis of LOPD includes inflammatory myositis, as both diseases share similar clinical and laboratory characteristics. We presented a case of a 30-year-old female initially diagnosed with polymyositis and treated with immunosuppressive therapy, but later found to have LOPD.