Consistent with this, roles in lipid droplet size regulation have also been defined for spastin binding partner atlastin-1 (ATL1) (Klemm et al., 2013), mostly responsible for autosomal dominant pure HSP (SPG3A), although more complex HSP clinical presentations have also been described associated with ATL1 gene mutation (Zhao and Liu, 2017). Here, ATL1 is linked to hereditary spastic paraplegia.