文摘
Genetic factors have been suggested to be involved in the pathogenesis of sporadic inclusion body myositis (sIBM). Sequestosome 1 (<em>SQSTM1em>) and valosin-containing protein (<em>VCPem>) are 2 key genes associated with several neurodegenerative disorders but have yet to be thoroughly investigated in sIBM. A candidate gene analysis was conducted using whole-exome sequencing data from 181 sIBM patients, and whole-transcriptome expression analysis was performed in patients with genetic variants of interest. We identified 6 rare missense variants in the <em>SQSTM1em> and <em>VCPem> in 7 sIBM patients (4.0%). Two variants, the <em>SQSTM1em> p.G194R and the <em>VCPem> p.R159C, were significantly overrepresented in this sIBM cohort compared with controls. Five of these variants had been previously reported in patients with degenerative diseases. The messenger RNA levels of major histocompatibility complex genes were upregulated, this elevation being more pronounced in <em>SQSTM1em> patient group. We report for the first time potentially pathogenic <em>SQSTM1em> variants and expand the spectrum of <em>VCPem> variants in sIBM. These data suggest that defects in neurodegenerative pathways may confer genetic susceptibility to sIBM and reinforce the mechanistic overlap in these neurodegenerative disorders.