Hereditary sensory and autonomic neuropathy type 5

Definition

A rare congenital sensory neuropathy characterized by selective or generalized loss of pain perception and impaired temperature sensitivity, in the absence of other abnormal neurological function. Patients present with variable severity of insensibility to pain and temperature. Self-mutilation of the lips, tongue, and fingers, painless injuries resulting in cuts, bruises, fractures, destroyed joints (Charcot joints) mostly in the knees and and feet are frequentyly observed. Patients have normal motor and sensory nerve conduction. Nerve biopsy typically manifest with reduced/absent small myelinated fibers whereas unmyelinated fibers are usually not affected. Episodic increase in body temperature, skin blotching, decreased sweating, poor wound healing, infections in teeth, joints and bone, neurotrophic keratitis, prematurely aged appearance, with malar hypoplasia, sunken eyes are reported in few patients. Mild intellectual disability may also be present.