Objective:

To describe the initial diagnosis, time from symptom onset to initiation of treatment, and current functional status of ten patients with late-onset Pompe disease who had originally received an incorrect diagnosis.

Background:

Pompe disease is an autosomal recessive glycogen storage disease caused by deficiency of acid alpha-glucosidase (GAA), which leads to the accumulation of lysosomal glycogen. Clinically, it is primarily characterized by weakness of the cardiac, respiratory, and skeletal muscles. Late-onset Pompe disease can present later in life and is thus underrecognized and frequently misdiagnosed, leading to delayed initiation of appropriate enzyme replacement therapy and subsequent increased morbidity and mortality for patients.

Design/Methods:

Case series describing ten patients who initially received an incorrect diagnosis but were ultimately diagnosed with late-onset Pompe Disease.

Results:

Five patients were initially diagnosed with limb-girdle muscular dystrophy, one with unspecified muscular dystrophy, two with inflammatory myositis, one with fatty liver disease, and one did not yet have a diagnosis but had already undergone two separate liver biopsies after elevated AST/ALT had been incidentally discovered. Average time from onset of symptoms to age of diagnosis was 14.4 years. Seven of the ten patients are known to currently be on enzyme replacement therapy and remain ambulatory (with or without assistive devices). The clinical status of the other three is unknown as they have been lost to follow up.

Conclusions:

Late-onset Pompe disease (LOPD) is underrecognized and can be misdiagnosed as a variety of other conditions including muscular dystrophy, inflammatory myositis, or even hepatic disease. These misdiagnoses lead to delays in initiation of treatment and result in morbidity and mortality for patients. There is need for education for physicians to recognize symptoms of LOPD and refer them accordingly.