CONGENITAL INSENSITIVITY TO PAIN AND ANHIDROSIS WITH MITOCHONDRIAL AND AXONAL ABNORMALITIES

Hereditary sensory and autonomic neuropathy type IV, or congenital ins ensitivity to pain with anhidrosis (CIPA), is a rare clinical disorder with only 32 cases reported in the literature, There has been no cons istent pathophysiologic defect of the sensory nerve detected by light microscopic examination, but a frequent finding of decreased small mye linated fibers and a uniform finding of decreased unmyelinated fibers by ultrastructural analysis has been reported, Muscle biopsy in a 2-ye ar-old bop with congenital insensitivity to pain with anhidrosis indic ated lipid droplet accumulation and reduced cytochrome C oxidase histo chemically on light microscopy. Electron microscopic study showed almo st absent small unmyelinated nerve axons within the muscle, increased microfilaments, and decreased microtubules in axons, some abnormally e nlarged mitochondria, and normal-appearing motor endplates, Biochemica l analysis of muscle mitochondrial enzyme function revealed cytochrome c oxidase function to be reduced to 35% of normal, with normal functi on of the other mitochondrial enzymes. (C) 1997 by Elsevier Science In c. All rights reserved.