Dominantly transmitted congenital indifference to pain.

Two patients from a family with dominantly inherited indifference to pain were investigated. Perception of the other sensory modalities was normal as was the remainder of the neurological examination. Electrophysiological studies and morphometric evaluation of myelinated and unmyelinated fibers of nerve biopsy specimens were normal. This is the first morphometric study of peripheral nerve in dominantly inherited indifference to pain.