Multisystem proteinopathy

This article may be too technical for most readers to understand. Please help improve it to make it understandable to non-experts, without removing the technical details. (December 2019) (Learn how and when to remove this message)

Multisystem proteinopathy (MSP) is a dominantly inherited, pleiotropic, degenerative disorder of humans that can affect muscle, bone, and/or the central nervous system. MSP can manifest clinically as classical amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), inclusion body myopathy (IBM), Paget's disease of bone (PDB), or as a combination of these disorders.^[1] Historically, several different names have been used to describe MSP, most commonly "inclusion body myopathy with early-onset Paget disease and frontotemporal dementia (IBMPFD)" or "inclusion body myopathy with frontotemporal dementia, Paget's disease of bone, and amyotrophic lateral sclerosis (IBMPFD/ALS)." However, IBMPFD and IBMPFD/ALS are now considered outdated classifications and are more properly referred to as MSP,^[1][2] as the disease is clinically heterogeneous and its phenotypic spectrum extends beyond IBM, PDB, FTD, and ALS to include motor neuron disease, Parkinson's disease features, and ataxia features.^[3][4] Although MSP is rare, growing interest in this syndrome derives from the molecular insights the condition provides into the etiological relationship between common age-related degenerative diseases of muscle, bone, and brain.