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Congenital insensitivity to pain
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Reviewed November 2012
What is congenital insensitivity to pain?
Congenital insensitivity to pain is a condition that inhibits the ability to perceive physical pain. From birth, affected individuals never feel pain in any part of their body when injured. People with this condition can feel the difference between sharp and dull and hot and cold, but cannot sense, for example, that a hot beverage is burning their tongue. This lack of pain awareness often leads to an accumulation of wounds, bruises, broken bones, and other health issues that may go undetected. Young children with congenital insensitivity to pain may have mouth or finger wounds due to repeated self-biting and may also experience multiple burn-related injuries. These repeated injuries often lead to a reduced life expectancy in people with congenital insensitivity to pain. Many people with congenital insensitivity to pain also have a complete loss of the sense of smell (anosmia).
Congenital insensitivity to pain is considered a form of peripheral neuropathy because it affects the peripheral nervous system, which connects the brain and spinal cord to muscles and to cells that detect sensations such as touch, smell, and pain.
How common is congenital insensitivity to pain?
Congenital insensitivity to pain is a rare condition; about 20 cases have been reported in the scientific literature.
What genes are related to congenital insensitivity to pain?
Mutations in the SCN9A gene cause congenital insensitivity to pain. The SCN9A gene provides instructions for making one part (the alpha subunit) of a sodium channel called NaV1.7. Sodium channels transport positively charged sodium atoms (sodium ions) into cells and play a key role in a cell's ability to generate and transmit electrical signals. NaV1.7 sodium channels are found in nerve cells called nociceptors that transmit pain signals to the spinal cord and brain. The NaV1.7 channel is also found in olfactory sensory neurons, which are nerve cells in the nasal cavity that transmit smell-related signals to the brain.
The SCN9A gene mutations that cause congenital insensitivity to pain result in the production of nonfunctional alpha subunits that cannot be incorporated into NaV1.7 channels. As a result, the channels cannot be formed. The absence of NaV1.7 channels impairs the transmission of pain signals from the site of injury to the brain, causing those affected to be insensitive to pain. Loss of this channel in olfactory sensory neurons likely impairs the transmission of smell-related signals to the brain, leading to anosmia.
Read more about the SCN9A gene.
How do people inherit congenital insensitivity to pain?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Where can I find information about diagnosis or management of congenital insensitivity to pain?
These resources address the diagnosis or management of congenital insensitivity to pain and may include treatment providers.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about congenital insensitivity to pain?
You may find the following resources about congenital insensitivity to pain helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for congenital insensitivity to pain?
What if I still have specific questions about congenital insensitivity to pain?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding congenital insensitivity to pain?
anosmia ; autosomal ; autosomal recessive ; cell ; channel ; congenital ; gene ; injury ; ions ; nervous system ; neuropathy ; nociceptors ; peripheral ; peripheral nervous system ; peripheral neuropathy ; recessive ; sodium ; sodium channel ; subunit
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (4 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.