Interestingly, patients with mutations in the SPAST gene associated with spastic paraplegia type 4 (SPG4) also present with SSR alterations and sudomotor dysfunction.102 Relevantly, like our patients, some SPG4 patients also show hyperreflexia and pyramidal signs with cerebellar ataxia.103 Some mutations in spastin protein causing SPG4 have been associated with microtubules and lysosomal trafficking,104 and it contains an AAA-ATPase domain predicted to be significant similar with the AAA-ATPase domain in SAMD9L identified in this study. Here, SPAST is linked to cerebellar ataxia.