Hereditary sensory and autonomic neuropathy is a genetically and clinically heterogeneous group of disorders characterized by degeneration of dorsal root and autonomic ganglion cells, and by sensory and/or autonomic abnormalities. Hereditary sensory and autonomic neuropathy type 5 (HSAN5) patients manifest loss of pain perception and impaired temperature sensitivity, in the absence of any other major neurological anomalies. Occasionally, the following features are observed; acral ulcers, increased susceptibility to Staphylococcus aureus infections and accidental injury to joints due to decreased sensation. The signs and symptoms of HSAN5 appear usually at birth or during infancy. Diagnosis is based upon clinical features as well as the degree of both sensory and autonomic dysfunction; HSAN5 patients have little reduction of C-fibers, the histamine test may be normal.
Karkashan et al. (2002) reported a 10 month-old girl, who was admitted to the hospital due to diarrhea and vomiting. It was noticed that she didn’t feel any pain on insertion of an intravenous line. Her mother noticed that she had no reaction to painful stimuli, like her 22 year old brother, who also had lacked reaction to painful stimuli since birth. Three other related family members, who trace back the same grandfather, have been noted to have same problem. All five patients lacked pain sensation from birth but have normal appreciation of other sensory modalities, normal tendon reflexes, normal sweating, and had normal intelligence. The affected siblings had painless injuries resulting in cuts, bruises, and fractures.
Carvalho et al. (2011) reported five siblings with HSAN5 from a consanguineous Emirati Bedouin family. The ages of the affecteds ranged from 2 to 12 years and they had the following symptoms; injury and ulceration of the lips and tongue because of pain insensitivity, temperature insensitivity, anhidrosis, mild mental retardation, prematurely aged appearance and frequent severe Staphylococcus aureus infections of the skin, teeth, joints, and bone.