Takeaway
An individual with a multisystem proteinopathy due to a homozygous valosin-containing protein gene (VCP) mutation has shared disease characteristics, but a more severe phenotype, than those with the heterozygous mutation.
Why this matters
The p.Arg159His VCP mutation was previously thought to only be pathogenic in the heterozygous state. These findings provide further information on VCP-related pathomechanisms.