Any hereditary spastic paraplegia in which the cause of the disease is a mutation in the AP4S1 gene. The disease is hereditary spastic paraplegia 52 (MONDO_0013552). Also known as: AP4S1 hereditary spastic paraplegia, CPSQ6, SPG52, Spastic Paraplegia 52, autosomal recessive spastic paraplegia 52, hereditary spastic paraplegia caused by mutation in AP4S1, hereditary spastic paraplegia type 52, spastic quadriplegic cerebral palsy 6.