A Comparison of Pathogenic Eukaryotic Elongation Factor 2 (EEF2) Variants in Spinocerebellar Ataxia 26 Versus De Novo Mutations

In this article, we present an eight-year-old boy with developmental delay and cerebellar symptoms who was found to have a de novo eukaryotic elongation factor 2 (EEF2) mutation on genetic testing. Previously, pathogenic mutations in EEF2 have been associated with spinocerebellar ataxia 26. An extremely rare disorder, spinocerebellar ataxia type 26 (SCA26), has only been documented as an autosomal dominant, inherited, late-onset ataxia in one six-generation family of Norwegian descent. However, three pediatric patients with de novo EEF2 mutations were recently discovered, presenting with noncerebellar symptoms such as syndactyly, developmental delay, and behavioral issues. The patient of this study was found to have features similar to both adult patients with SCA26 as well as previous pediatric patients with de novo mutations.