The following description is based on the Mao et al., article published in the American Journal of Human Genetics in 2020.
Growth parameters
The single individual currently identified with a pathogenic EIF2AK1 mutation has age-appropriate growth parameters.
Neurological features
The individual identified with LEMSPAD syndrome had developmental delay that primarily manifested as delayed walking (at 21 months) with an abnormal spastic gait and toe-walking. Additional features include speech delay and dysarthria with poor articulation, lower-extremity hypertonia, progressive spasticity, hyperreflexia, and bradykinesia, anxiety and attention deficit-hyperactivity disorder. The individual reported had normal cognition and attended a mainstream school with accommodations. Her nerve conduction studies were found to be normal.
Brain imaging at age 2 years showed nonspecific T2-weighted hyperintensities at the posterior lateral ventricles and periventricular gliosis. Mid-sagittal T1-weighted image showed appropriate size of corpus callosum and cerebellar vermis. There were no myelination defects found.