Genetics

Updated 22 August 2017

Meet the boy who can’t feel pain

Could you imagine living your entire life feeling no pain at all? Meet the boy who doesn’t feel anything when he gets injured.

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When children hurt themselves, everyone within a 100m radius is normally deafened by their screams.

This is, however, not the case for three-year-old Dexter Cahill, a UK toddler who was born with hereditary sensory and autonomic neuropathy (HSAN) type IV, a rare disorder which causes one to feel no pain. He is also unable to distinguish between hot and cold.

Bumps, scratches, cuts and bruises

Because the little one is unable to feel pain, he also doesn't cry. While some parents may consider this an advantage, Cahill's parents probably wouldn't wish it on their worst enemies.

Earlier this year, Dexter was jumping up and down during a dance session at school, but after a few beats, he fell down and couldn't get up again. The staff discovered he had broken his shin bone. Dexter's mom, distraught and crying, rushed to his school only to find her son in no pain and confused as to why so many people were making a fuss over him.

Cahill's mom told the Daily Mail that when her son broke his tibia in his left shin, doctors were able to set his bone and put on the cast without any pain medication.

During his short life, Cahill has already broken his thumb, his hand, his shin bone, as mentioned, and shattered a bone in his foot.

His mom also details how her son is regularly covered in bumps, scratches, cuts and bruises without knowing where they came from. She added that he also pulled out three of his teeth.

Their new home has air conditioning installed because Cahill also suffers from anhidrosis, which means he doesn't sweat and is unable to gauge temperature.

Those who have HSAN type IV do have sensory nerves, but they function abnormally. These nerves are meant to control pain and temperature, but in his case they are unable to because of the genetic disorder.

Mutation of a gene

The condition is considered extremely rare and it manifests either at birth or during infancy, according to the Genetic and Rare Diseases Information Centre (Gard). It took doctors and specialists over a year to diagnose Cahill's condition.

Gard states that the cause of the disorder is due to a mutation of a gene meant to produce a certain type of protein that aids the development and sustainability of the nerve cells which transmit information about pain, temperature and touch.

The National Organisation for Rare Disorders (NORD) lists many symptoms of the disorder. Some examples are:

  • Impaired or lack of pain sensation
  • Anhidrosis – the inability to sweat and regulate body temperature
  • Unintentional self-harm (due to lack of pain sensation)
  • Repeated fractures, joint damage and possible osteomyelitis (bone infection)
  • Various skin conditions as a result of anhidrosis
  • Possible intellectual disability

Congenital condition

The Indian Journal of Paediatric Dermatology published a case report in 2014 of a little girl who suffers from the same genetic disorder.

In the report, the doctors tell how the 18-month-old toddler was first referred to the psychiatric department for self-mutilation, before being referred to them.

They also detail how she had suffered from numerous painless ulcers and how she started biting her mouth, the tip of her tongue and fingers once she had started teething. The report also tells of how the toddler's mother noticed her daughter wouldn't cry after experiencing something normal babies would consider painful, like an injection.

Because the condition is congenital – inherited from birth – a cure is unlikely, but parents of children who have the condition monitor them closely and mitigate every possible risk. Children who have the disorder basically need to learn how to not hurt or harm themselves.

Diagnosis and treatment

Once specialists identify certain characteristics and traits, such as self-mutilation, lack of perspiration and possible intellectual disability, they look into a patient's history and begin a course of rigorous tests.

While the disorder cannot be cured, specialists look towards treating the specific symptoms, which differ from patient to patient. Families should consider making the environment as safe as possible, so that certain conditions and illnesses which come as a result of the disorder, are more manageable.

Specialists also advise that families go for counselling to help manage the psychological factors — for someone suffering from the disorder and those family members who are closely involved with the affected.

Image supplied by iStock.