Adult-Onset Spinal Muscular Atrophy due to Mutations in the <i>VRK1</i> Gene
Angela Sung, Paolo Moretti, Aziz Shaibani
Abstract
<h3>Objective</h3> To expand our knowledge of the range of clinical phenotypes associated with vaccinia-related kinase 1 (<i>VRK1</i>) gene mutations. <h3>Methods</h3> We present clinical and molecular data of 2 individuals with slowly progressive weakness and a clinical syndrome consistent with adult-onset spinal muscular atrophy without pontocerebellar atrophy. <h3>Results</h3> Genetic testing revealed likely pathogenic variants in the <i>VRK1</i> gene in both subjects. One individual carried homozygous p.R321C (c.961 C>T), likely pathogenic variants. The other carried compound heterozygous p.V236M (c.706 G>A) and p.R321C (c.961 C>T), likely pathogenic variants. Notably, both patients were of Hispanic descent. <h3>Conclusions</h3> We report 2 cases with <i>VRK1</i> mutations presenting as adult-onset spinal muscular atrophy without pontocerebellar hypoplasia and review the current literature of similar cases. Our report expands the clinical spectrum of neurologic disorders associated with <i>VRK1</i> mutations.