Congenital Insensitivity To Pain (CIP): Causes, Symptoms, Complications, Diagnosis And Treatment

Congenital insensitivity to pain or (CIP) is a rare genetic disorder of the nervous system in which a person is unable to perceive any kind of physical pain. It is an autosomal recessive disorder, meaning an inherited disorder caused when the two copies of abnormal gene get transferred to the child and cause the trait for this problem to develop. The disorder is usually present at the birth of an individual ^[1] .

People with CIP are unable to feel pain in any body parts due to lack of senses. For example, they cannot sense whether a certain object is hot or cold and are unable to detect any wound in their body parts which often cause them multiple injuries, infection, broken bones and other serious health problems due to lack of senses. Due to the repeated injuries, their life expectancy is also decreased.

CIP is also considered a type of peripheral neuropathy, a disorder of the peripheral nervous system which is responsible for the exchange of signals (smell, touch and pain) between the central nervous system and other body parts or vice versa ^[2] .

CIP is known by several names. The other names of CIP include the following:

• Congenital sensory, with anhidrosis ^[2]
• Neuropathy
• Hereditary sensory and autonomic neuropathy 4
• Familial dysautonomia, type II

Causes Of Congenital Insensitivity To Pain

A gene named SCN9A is responsible to provide instructions to the body to make a part of the alpha subunit (protein) called Nav1.7 which is responsible for the transmission of electric signals (pain, heat and cold) to the brain and spinal cord.

The mutation in the gene SCN9A causes nonfunctional alpha subunits leading to the death of the neurons. This results in the loss of sensory neurons, causing an obstruction in the passage of pain signals from the affected body parts to the brain, hence leading to CIP ^[3] .

Symptoms Of Congenital Insensitivity To Pain

Symptoms of people with CIP vary from individual to individual. Common symptoms of the condition are as follows:

• Seizures due to hyperthermia, as people with CIP, are often unable to sweat (anhidrosis) ^[4]
• Unable to feel pain ^[1]
• Unable to feel the temperature
• Loss of smell, anosmia ^[5]
• Loss of bladder control ^[6]
• Severe spasticity of the lower limbs ^[7]

Complications Of Congenital Insensitivity To Pain

Complications of CIP include the following:

• Severe burn or injuries ^[1]
• Painless fractures ^[8]
• Infection due to insensitivity to wounds ^[9]
• Corneal abrasions due to decreased tear production ^[10]
• Anhidrosis, loss of very less production of sweat ^[11]
• Urinary incontinence ^[1]
• Chronic anaemia ^[12]

Diagnosis Of Congenital Insensitivity To Pain

Diagnosing CIP can be problematic for healthcare experts. It is carried out by the following processes:

• Medical history: To get a detailed view of the symptoms of a patient with CIP and rule out other similar conditions.
• Genetic Testing Registry (GTR): A comprehensive genetic test information about the patient who has voluntarily submitted it for testing ^[13] .

Treatment Of Congenital Insensitivity To Pain

There is still no cure available for treating CIP. However, the condition can be managed by controlling the complications of the disorder. As it develops from birth, parents and caretakers of a child with CIP should be careful and provide immediate medical attention when any of the complications occur. For serious bone problems in children, surgeries are advised while for infection, wounds, and loss of tear production, related drugs are prescribed ^[1] .