Case 1 possibly had pure HSP associated with heterozygous SPG11, as no other cause could be ascertained from the patient’s spinal cord MRI, metabolic scans, and whole-exome sequencing (WES) analysis other than brain MRI, which was consistent with hypoplasia of the vermis, cerebellum, and corpus callosum (Figure 1) (Table 2). The gene discussed is SPG11; the disease is hereditary spastic paraplegia.