Clinically, patients with mutations in SPTLC1 or SPTLC2 are phenotypically indistinguishable and mutations in both genes have been suggested to cause HSN-1 via the same mechanism of dysregulated sphingolipid metabolism (Rotthier et al., 2012). Here, SPTLC2 is linked to hereditary sensory and autonomic neuropathy type 1.