[Inclusion body myositis, Paget's disease of the bone and frontotemporal dementia: early involvement of the heart and respiratory muscles].
Since valosin-containing protein mutations were reported as a cause of hereditary inclusion body myositis associated with Paget's disease of the bone and frontotemporal dementia, many new mutations have been described in the last decade. We report on a 46-year-old German male with a progressive tetraparesis and autosomal dominant inheritance pattern. Echocardiography revealed a beginning dilated cardiomyopathy and laboratory analyses showed increased alkaline phosphatase. Decreased verbal memory and an impairment of concept building were observed on neuropsychological examination. Muscle biopsy demonstrated a myopathic pattern, rimmed vacuoles, CD8+ T-cell infiltrates and positive MHC1-muscle fibres. We found a heterozygote mutation in exon 5 of the valosin-containing protein gene (c.464G > T p.Arg155Leu), which until now has been described only in an Australian family. We describe here the first German case with the above-mentioned mutation causing inclusion-body myositis associated with Paget's disease of the bone and fronto-temporal dementia. Here, we recommend regular controls of cardiac and respiratory functions.