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Screening for late‐onset Pompe disease in undiagnosed myopathies
Author(s) -
Matsui Misa,
Inoue Kimiko,
Sakoda Saburo,
Matsumura Tsuyoshi,
Hamazaki Takashi,
Kosuga Motomichi,
Okuyama Torayuki,
Shimada Yohta,
Ohashi Toya,
Nishino Ichizo
Publication year - 2017
Publication title -
neurology and clinical neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.125
0ISSN - 2049-4173
DOI - 10.1111/ncn3.12108
Subject(s) - medicine , disease , dried blood spot , muscle biopsy , myopathy , glycogen storage disease type ii , alpha (finance) , biopsy , fabry disease , gastroenterology , pediatrics , enzyme replacement therapy , surgery , genetics , construct validity , patient satisfaction , biology
Background Pompe disease is caused by a deficiency of acid alpha‐glucosidase. Its prevalence varies depending on ethnicity, and is less prevalent in Japan as compared with other countries. Because of the wide spectrum of clinical features in late‐onset cases, some patients might be misdiagnosed with another myopathy, thus the actual prevalence in Japan might not be accurately reported. Aim To clarify the actual prevalence of late‐onset Pompe disease, we investigated acid alpha‐glucosidase activity in patients with undiagnosed myopathies. Methods Of 42 patients with undiagnosed myopathies, 41 underwent assessment of acid alpha‐glucosidase enzyme activity using dried blood spot analysis. As a second step, reassessment of acid alpha‐glucosidase activity was carried out using cultured skin fibroblasts. We also determined acid alpha‐glucosidase activity in biopsied muscle tissue obtained from the one other patient, who had previously undergone a muscle biopsy. Finally, gene analysis was carried out to confirm diagnosis. Results Four patients showed reduced acid alpha‐glucosidase activity in dried blood spot findings, of whom one possessed a pseudo‐deficiency allele. Furthermore, one patient who showed reduced acid alpha‐glucosidase activity in a biopsied muscle specimen was diagnosed with late‐onset Pompe disease based on gene analysis. Conclusions Of the present 42 patients, only one patient was diagnosed with late‐onset Pompe disease. The prevalence of Pompe disease in Japan does not seem to be as high as in other countries, though a certain number of patients might exist among those with undiagnosed myopathies. A larger and more systematic survey is necessary to elucidate the actual prevalence of late‐onset Pompe disease in Japan.