• A male infant had sensory and autonomic dysfunction, and his identical twin had a similar clinical finding. One twin was extensively studied, utilizing sural nerve, skin, and conjunctival biopsy specimens, to evaluate the status of peripheral sensory axons. The results support an antenatal neurodevelopmental disturbance in axonal growth that affects sensory neurons and limits their distal extension. Neuropathologic studies of this patient closely resemble findings in hereditary sensory neuropathy type II; clinically, however, this patient resembles patients with congenital autonomic dysfunction and universal pain loss. Investigation of proximal and distal sural nerve, skin, and/or conjunctival biopsy specimens is recommended in patients with sensory and autonomic dysfunction to help differentiate these patients to assist in genetic counseling, treatment, and prognosis. It is possible that clinical overlap in such patients may result from a common neuropathic process, but with varying degrees of involvement.