Expanding the spectrum of SPTLC1-related disorders beyond hereditary sensory and autonomic neuropathies: a novel case of the distinct "S331 syndrome"

Hereditary sensory and autonomic neuropathies (HSAN) encompass a group of peripheral nervous system disorders characterized by remarkable heterogeneity from a clinical and genetic point of view. Mutations in SPTLC1 gene are responsible for HSAN type IA, which usually starts from the second to fourth decade with axonal neuropathy, sensory loss, painless distal ulcerations and mild autonomic features, while motor involvement usually occur later as disease progresses.