<i>EEF2</i>-Related Neurodevelopmental Disorder Is Clinically Recognizable

Abstract

<b><i>Introduction:</i></b> <i>EEF2</i> encodes eukaryotic elongation factor 2 which catalyzes the elongation phase of protein translation. It is ubiquitously expressed and important for neuronal function. <i>EEF2</i> was first associated with adult-onset spinocerebellar ataxia type 26 (SCA26). A novel neurodevelopmental disorder associated with de novo heterozygous variants in <i>EEF2</i> has been described. Only 6 patients have been described in the literature thus far. A 9-year-old child with de novo novel missense variant is described here. <i>EEF2</i>-related neurodevelopmental disorder appears to be clinically recognizable. <b><i>Case Presentation:</i></b> A nine-year-old male with autism spectrum disorder was referred for genetic evaluation. On examination, he had relative macrocephaly and frontal prominence. Whole exome sequencing revealed a de novo c.1225 C&gt;T: p. (R409W) variant in exon 9 of the <i>EEF2</i> gene (NM_001961.3). <b><i>Discussion:</i></b> A comparison of clinical findings suggests that relative macrocephaly/macrocephaly and prominent forehead are consistent and easily identifiable clinical features of <i>EEF2</i>-related neurodevelopmental disorder. The clinical spectrum of this disorder is still emerging. <i>EEF2</i>-related neurodevelopmental disorder should be considered in a child with autism, developmental delays/intellectual disability, macrocephaly/relative macrocephaly, and frontal prominence.