Other less common types of autosomal recessive HSP include SPG39, SPG46, SPG52, SPG53, SPG76, as well as mutations in kinesin light chain 2 (KLC2), phosphate cytidylyltransferase 2, ethanolamine (PCYT2), autocrine motility factor receptor (AMFR), ubiquitin E3 ligase RNF170, Human 4-hydroxyphenylpyruvate dioxygenase-like (HPDL), and Coenzyme Q4 (COQ4) have also been identified. The gene discussed is PNPLA6; the disease is hereditary spastic paraplegia.