Variants in the cytoplasmic domains of SPTLC1 and SPTLC2 result in pathologically increased 1-deoxySL levels, causing hereditary sensory and autonomic neuropathy type 1 (HSAN1) (8, 9), an autosomal dominant axonopathy characterized by a progressive sensory loss with variable autonomic involvement (10–13). This evidence concerns the gene SPTLC1 and hereditary sensory and autonomic neuropathy type 1.