Inclusion body myopathy with paget disease of bone and frontotemporal dementia linked to VCP p.Arg155Cys in a Korean family

Background: Missense mutations in the valosincontaining protein (VCP) gene on chromosome 9p13.3-p12 cause inclusion body myopathy with Paget disease of bone and frontotemporal dementia (hereafter referred to as IBMPFD; OMIM 167320). Objective: To describe detailed clinical, electrophysiological, biochemical, and neuroimaging findings in IBMPFD linked to VCP p.Arg155Cys in a Korean family. Design: Case series. Clinical, electrophysiological, biochemical, and neuroimaging findings were obtained by direct evaluation and from previous medical records. Setting: Tertiary referral hospital. Participants: Three affected family members in a Korean family. Results: The clinical features of myopathy, Paget disease of bone, and semantic dementia (a clinical subtype of frontotemporal dementia) in our patients were similar to those of previously reported cases. However, the brain magnetic resonance imaging features in our patients, including asymmetric anterior and lateral temporal and inferior parietal atrophy with ventricular dilatation on the affected side, differed from those of previously published features in patients with IBMPFD and in patients with typical semantic dementia who show anterior temporal and frontal atrophy. Conclusion: To our knowledge, this report provides the first documented IBMPFD family in Asia and broadens the phenotypic spectrum of VCP mutation-associated frontotemporal dementia.