Notwithstanding, the expression pattern using Na+, K+ ATPase showed that the mutated NIPA1 protein was concentrated in a perinuclear distribution, whereas the WT protein was distributed throughout the cytoplasm (Figure S3), suggesting an abnormal trafficking of mutated proteins as was established for the NIPA1-associated HSP phenotype [26,27]. The gene discussed is NIPA1; the disease is hereditary spastic paraplegia.