In addition to BFNIS, de novo dominant mutations in SCN2A can cause also more severe seizure syndromes (Kamiya et al., 2004; Ogiwara et al., 2009; Liao et al., 2010a; EIEE11; OMIM 613721): as recently reviewed (Baasch et al., 2014), 14 mutations in Nav1.2 appear to relate with BFNIS and 21 mutations with more severe phenotypes, including developmental delay and intractable seizures. This evidence concerns the gene SCN2A and Global developmental delay.