Rinsho Shinkeigaku (Clinical Neurology)

Case Report

A case of Japanese Laing type distal myopathy with a mutation in MYH7 gene

Kenju Hara, M.D., Ph.D.1), Hajime Miyata, M.D., Ph.D.2) and Ichizo Nishino, M.D., Ph.D.3)

1)Department of Neurology, Akita Red Cross Hospital
2)Department of Neuropathology, Akita Cerebrospinal and Cardiovascular Center
3)Department of Neuromuscular Research, National Institute of Neurology, National Center of Neurology and Psychiatry

A 67-year-old man developed weakness and atrophy of the anterior compartment of the lower leg at age 53 years, followed by weakness of proximal muscles of the upper limb. His father had difficulties in walking in his thirties and died of heart disease at age 45 years. He also had mild respiratory weakness without cardiac involvement. Muscle histology showed spheroid or cytoplasmic bodies-like inclusions with moth-eaten appearance and irregular intramyofibrillar network. Electron microscopy revealed abnormally thickened and disorganized Z lines (Z line streaming) between the surrounding myofibrils and electron-dense globular deposits. These pathological findings apparently suggested myofibrillar myopathy. However, genetic analysis revealed a mutation (c.5566G>A, p.E1856K) in MYH7 gene, that is responsible for Laing-type distal myopathy (LDM). This mutation was previously reported in a study from Austria. This is the first report of LDM in the Japanese population.
Full Text of this Article in Japanese PDF (1129K)

(CLINICA NEUROL, 59: 823|828, 2019)
key words: distal myopathy, Laing type, MYH7 gene, myofibrillar myopathy

(Received: 4-Jul-19)