ZFYVE26 and hereditary spastic paraplegia: To date, more than 82 gene loci have been found to cause HSP, and SPG15 (<i>ZFYVE26</i>) is one of the most common autosomal recessive hereditary spastic paraplegias (ARHSPs) with a thin corpus callosum (TCC), presents with early cognitive impairment and slowly progressive leg weakness.