AKAP11 variants associate with neuropsychiatric disease49; ARHGEF9 mutations cause intellectual disability50; and MECP2 mutations also cause severe intellectual disability through loss of function in Rett’s syndrome51 and increased dosage in MECP2 duplication syndrome51,52, with MECP2 overexpression impairing cognition and synaptic transmisssion52. The gene discussed is MECP2; the disease is Intellectual disability.