A single RTT-like patient harboring an actin-like protein 6b (ACTL6B) gene variant with EE (IS at 3 months), followed by bilateral tonic-clonic seizures and generalized cerebral atrophy, with severe DD (non-verbal and non-ambulant) and hand wringing stereotypies but no history of regression was reported [52]. The gene discussed is ACTL6B; the disease is Global brain atrophy.