The objective of this study is to report a Brazilian patient and his family with inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia (IBMPFD). A systematic review of the literature on the valosin-containing protein (VCP) mutation was also performed. The proband (patient) was initially treated as a case of possible refractory polymyositis with Paget's disease and later as an inclusion body myopathy. However, after admission to our service, and considering his personal and familial antecedents, whole exome sequencing was performed revealing valosin-containing protein (VCP) c.290G>A (p.Gly97Glu) mutation in the patient and his nine family members. The clinical presentation of the patient and his family was characterized by different degrees and evaluations of IBMPFD. According to the literature, only one family (Chinese) has this same VCP mutation concomitantly with different IBMPFD phenotype manifestations. The present study shows that IBMPFD should be considered as a differential diagnosis in patients with inflammatory myopathies associated to bone disease and/or cognitive impairment. Moreover, the study expands the genotypic spectrum of missense mutations of VCP gene in a Brazilian family with variable phenotypes.
Keywords: Bone disease; Dementia; Gene mutation; Myopathy; Myositis.