MONDO_0013401 (hereditary spastic paraplegia 51) is any hereditary spastic paraplegia in which the cause of the disease is a mutation in the AP4E1 gene. Also known as: AP4E1 hereditary spastic paraplegia, CPSQ4, SPG51, Spastic Paraplegia 51, autosomal dominant spastic paraplegia 51, hereditary spastic paraplegia caused by mutation in AP4E1, hereditary spastic paraplegia type 51, spastic quadriplegic cerebral palsy 4.