Rinsho Shinkeigaku (Clinical Neurology)

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Inclusion body myopathy with Paget's disease of bone and frontotemporal dementia

Yukiko Hayashi, M.D., Ph.D.1)

1)Department of Neurophysiology, Tokyo Medical University

Inclusion body myopathy with Paget's disease of bone and frontotemporal dementia (IBMPFD) is an autosomal dominant disease caused by mutations in the VCP gene. VCP encodes a well-conserved multifunctional protein, valosin containing protein (VCP), which has important roles in protein quality control via proteasome and autophagy, protein aggregation, quality control of mitochondria, cell proliferation, and so on. Clinically, muscle weakness is the most common symptom of which disease onset is around 40 years. Affected muscles are variable, and the patients are sometimes diagnosed as limb girdle muscular dystrophy or GNE myopathy. Muscle pathology shows characteristic features including cytoplasmic/nuclear inclusions, rimmed vacuoles, and disorganized myofibrills, together with neurogenic changes. Paget's disease of bone is reported to be observed in a half of the patients around the age of 40 years, but less common in Japanese patients. Frontotemporal dementia is seen around one third of the patients which appears nearly 10 years later than muscle or bone disease. In addition to cognitive dysfunctions, motor neuron involvement and cerebellar signs were also seen in our series. IBMPFD is not so rare disease as previously thought, but complicate clinical findings may make its diagnosis difficult.
Full Text of this Article in Japanese PDF (4844K)

(CLINICA NEUROL, 53: 947|950, 2013)
key words: VCP, tubulofilamentous inclusion, rimmed vacuole, myofibrillar myopathy, neurogenic changes

(Received: 31-May-13)