Some of the nominally associated genes have been linked to Mendelian disorders with neurological symptoms, including Walker-Warburg syndrome, a congenital muscular dystrophy with brain and eye abnormalities (ISPD OMIM: 614643, POMK OMIM: 615249); nocturnal frontal lobe epilepsy type 1 (CHRNA4 OMIM: 600513); generalized epilepsy (GABRD OMIM: 613060); spastic paraplegia 51, an autosomal recessive developmental disorder with severe intellectual disability (AP4E1 OMIM: 613744); and Batten disease, an autosomal recessive neurodegenerative condition (CLN3 OMIM: 204200). The gene discussed is AP4E1; the disease is Intellectual disability.