Hereditary sensory and autonomic neuropathy type 1 (HSAN 1) is a dominantly inherited disorder; its gene locus is mapped on chromosome 9q22. Three different missense mutations (C133Y, C133W and V144D) have been described in 11 families from Australia, England and Austria. Common clinical features have been found in these families. We report the clinical and electrophysiological features of three members of a large Portuguese family with HSAN 1 and the C133Y missense mutation. The affected members showed typical clinical features. Electrophysiological findings were consistent with a distal axonal predominantly sensory neuropathy with motor involvement, in three different severity stages. No autonomic involvement was detected in sudomotor and cardiovascular tests. This report documents the lesion of the motor nerve fibers in this disease, as well as the preservation of the autonomic nervous system function, therefore suggesting that HSNA is an inappropriate name for this disorder.