On the contrary, GBA2-knockdown zebrafish show abnormal motor neuron development [21], and mutations in the human GBA2 gene have been found to lead to neurological disorders like spastic ataxia (SA) [22,23], hereditary spastic paraplegia (HSP) [21,24,25], and more recently Marinesco-Sjogren-Like Syndrome [26]. This evidence concerns the gene GBA2 and hereditary spastic paraplegia.