Hereditary Sensory and Autonomic Neuropathy IV (HSAN IV)

Congenital insensitivity to pain with anhidrosis is a rare form of hereditary sensory and autonomic neuropathy. Characteristic features are indifference to painful stimuli, self-mutilating behavior, anhidrosis (inability to sweat), corneal ulcers, and sometimes hypogammaglobulinemia and recurrent infections, skin changes, osteomyelitis, bone fractures, and cognitive impairment. The patients\' inability to sweat usually leads to recurrent episodes of unexplained fever and can be fatal due to hyperthermia, especially in infants and small children. The lack of pain sensation is thought to stem from the absence of the dorsal root ganglia responsible for pain sensation, while anhidrosis is due to the loss of innervation of eccrine sweat glands by sympathetic neurons.

Tests Available

Forms and Documents

Test Details

  • Confirmation of the clinical diagnosis
  • Carrier testing in unaffected family members
  • Prenatal diagnosis in families with an affected child and known mutation(s)


3 weeks
2-5 mL Blood - Lavender Top Tube
Buccal Swabs

*Reporting times are typical, but could be extended in situations outside GeneDx's reasonable control.


  • 705 Disorders of sweat glands
  • 778.4 Other disturbances of temperature regulation of newborn, Dehydration fever in newborn, Environmentally induced pyrexia, Hyperthermia in newborn, Transitory fever of newborn
  • 742.8 Other specified anomalies of nervous system, Agenesis of nerve, Displacement of brachial plexus, Familial dysautonomia, Jaw-winking syndrome, Marcus-Gunn syndrome, Riley-Day syndrome
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**The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.


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  5. Kilic S, et al. Neurogenetics. 2009; 10:161-5