Our findings suggest that for the seizure phenotype, the brain is more sensitive to reduced eIF5A hypusination caused by mutations in DHPS or DOHH, while patients with neurodevelopmental disorders caused by autosomal dominant EIF5A mutations do not exhibit seizures as remaining eIF5AHYP levels may be sufficient to prevent epileptiform activity and seizures. The gene discussed is DHPS; the disease is neurodevelopmental disorder.