Hereditary sensory autonomic neuropathy type IIa (HSAN type IIa) is an inherited peripheral neuropathy. Peripheral neuropathy is pain and weakness caused by damage to sensory neurons. Sensory neurons send signals to the brain about touch, pain, temperature, and other physical sensations.
The first symptom of HSAN type IIa is often inflammation and numbness in the hands and feet. Further symptoms include an inability to sense pain and temperature. Sometimes, autonomic neurons are also affected. These neurons control body functions like breathing and heart rate. When these neurons do not work properly, symptoms include digestive problems and slow reflexes. Individuals may also have untreated injuries in their hands, feet, limbs, and joints because of their inability to feel pain.
HSAN type IIa is caused by a mutation (change) in the WNK1 gene. If a mistake or error occurs in a gene, it can cause problems. We inherit our genes in pairs, one from each parent typically. HSAN type IIa is inherited in an autosomal recessive manner. Autosomal recessive means that an individual must have two copies of the changed gene or mutation that causes the condition. A person with one changed gene would be a carrier of the condition but usually will not have any symptoms. If both parents are carriers of the condition, each child has a one in four chance (25%) of having the disease.
HSAN type IIa is diagnosed through examination of symptoms and patient history, as well as through genetic testing of the WNK1 gene. Treatment depends on specific symptoms, but often includes teams of neurologists, orthopedic surgeons, and physiotherapists. Treatment is also focused on taking extra care of limbs that have no sensation and on wound cleaning. If you or a family member has been diagnosed with hereditary sensory autonomic neuropathy type IIa, talk to your doctor about the most current treatment options.
Description Last Updated: Mar 07, 2018