Neurodevelopmental disorder with hypotonia and seizures (NEDHS) is an autosomal recessive disorder characterized by hypotonia apparent from early infancy, global developmental delay with severely impaired intellectual development, and early-onset seizures. Heterozygous mutation carriers show a milder neurocognitive disorder with learning disabilities, similar to chromosome 15q13.3 deletion syndrome (Garret et al., 2020; Suzuki et al., 2021).