SPTLC1 and hereditary sensory and autonomic neuropathy type 1: The accumulation of DSBs has been linked to Hereditary sensory and autonomic neuropathy type 1 41, 66, with the observation that high dose L-serine supplementation lowers plasma DSB levels and alleviates neuronal symptoms in HSAN1 patients, whereas alanine increases DSB levels and worsens peripheral neuropathy 67.