Rinsho Shinkeigaku (Clinical Neurology)

Case Report

Electrophysiological evidence of impaired neuromuscular junction in a case of phosphoglucomutase 1 deficiency manifesting fluctuating muscle weakness

Yu Takenaka, M.D.1)2), Kenji Sekiguchi, M.D., Ph.D.1), Hiroaki Sekiya, M.D., Ph.D.1), Kinji Ohno, M.D., Ph.D.3), Hideo Sugie, M.D., Ph.D.4) and Riki Matsumoto, M.D., Ph.D.1)

1)Division of Neurology, Kobe University Graduate School of Medicine
2)Hyogo-Chuo National Hospital
3)Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine
4)Faculty of Health and Medical Sciences, Tokoha University

A 27 year-old Canadian man suffered from fluctuating muscle weakness in the past several years. The patient had a past history of intestinal bleeding, bifid uvula and hypothyroidism in his childhood. Repetitive nerve stimulation tests showed a decrement pattern in the left deltoid muscle. The single fiber electromyography of the left extensor digitorum muscle showed an increment of jitter. Both findings were improved by the edrophonium test. He was diagnosed as having phosphoglucomutase 1 (PGM1) deficiency, as the compound heterozygote mutation of the PGM1 gene was recognized in the whole-exome sequencing and the enzyme activity of PGM1 was defective in the biopsied muscle. Treatment with the galactose lead to improvement of the fluctuating muscle weakness and decremental pattern in the repetitive stimulation test. PGM1 deficiency should be listed in the differential diagnosis of the neuromuscular junction disorder, when the patient is seronegative for antibodies related with myasthenia gravis and shows symptoms or signs consistent with PGM1 deficiency.
Full Text of this Article in Japanese PDF (1194K)

(CLINICA NEUROL, 60: 152－156, 2020)
key words: phosphoglucomutase 1 deficiency, congenital disorder of glycosylation, glycogenosis type XIV, repetitive stimulation test, the neuromuscular junction disorder

(Received: 4-Oct-19)