What is HSAN-IV?
Type IV Hereditary Sensory and Autonomic Neuropathy, also known as Congenital Insensitivity to Pain with Anhidrosis (CIPA), is characterized by the loss of pain and temperature perception in addition to the lack of sweating. [1] A congenital disease, HSAN-IV is present at birth and is caused by inheriting a copy of the mutated gene by both parents, and occasionally, two mutated genes from one parent. Though directly not life-threatening, the lack of pain and temperature perception can leave underlying problems in the body undetected and unresolved.
What is Anhidrosis?
Anhidrosis is the lack of sweating.[1] Lack of sweating under abnormal heat conditions or during bodily exhertion can lead to overheating and potentially a heatstroke. Though HSAN-IV is not always the underlying cause of anhidrosis, those diagnosed with CIPA/HSAN-IV cannot sense temperature from cold and warm temperature sensors.[2]
Physical Symptoms:
Physical symptoms of HSAN-IV usually stem from the effects of the inability to feel pain. Though these physical symptoms do not indicate that a person has HSAN-IV, they can possibly be the effects of someone with HSAN-IV.
- Bone fractures
- Cuts and bruises
- Signs of self-mutilation in the mouth, lips, fingers, skin
- Joint trauma
- Absence of sweating
- Unexplained fever [3]
To learn more about HSAN-IV please see the sections:
Physiology
Pathophysiology
Current Research and Treatment
Physiology
- Nociceptors
- Sensory Pathways
- Pain and Temperature Pathways
- Neurons
- Membrane Potential
- Graded/Action Potential
Pathophysiology
- Non-functioning voltage gated sodium ion channels
- Non functioning nerve growth proteins
Current Research and Treatment
- NGF-encoding gene
- NTRK1 gene
- Naloxone
References
- Axelrod FB, Gold-von Simson G, Oddoux C. Hereditary Sensory and Autonomic Neuropathy IV. 2008 Aug 5 [Updated 2009 Nov 24]. In: Pagon RA, Bird TD, Dolan CR, et al., editors. GeneReviews™ [Internet]. Seattle (WA): University of Washington, Seattle; 1993-.Available from: http://www.ncbi.nlm.nih.gov/books/NBK1769/
- Silverthorn, DU. Human Physiology. San Francisco: Pearson. p 249-263.
- Mardy S, Miura S. Congenital insensitivity to pain with anhidrosis: novel mutations in the TRKA(NTRK1) gene encoding a high-affinity receptor for nerve growth factor. The American Journal of Human Genetics. 1999; 64(6):1570-1579.