From CNN’s “World without pain is hell, parent says“:
Roberto is one of 17 people in the United States with “congenital insensitivity to pain with anhidrosis,” referred to as CIPA by the few people who know about it. …
Other abnormalities quickly surfaced. Roberto was severely susceptible to heatstroke on hot summer days. His parents soon noticed he did not sweat.
“You can’t carry Roberto because he sucks your heat from your body. You’re hot, sweaty. His body can’t sweat like yours so he’s just absorbing all of your heat,” Stingley-Salazar said.
His family was shocked when Roberto started teething. He gnawed on his own tongue, lips and fingers to the point of mutilation. …
Axelrod has studied this family of “no-pain” diseases for more than 35 years. These genetic disorders affect the autonomic nervous system — which controls blood pressure, heart rate, sweating, the sensory nerve system and the ability to feel pain and temperature. …
CIPA is the most severe and fatal type of the seven types of hereditary sensory and autonomic neuropathy, or HSAN. Overheating kills more than half of all children with CIPA before age 3, Stingley-Salazar said.
According to Axelrod, levels of pain vary.
“For some children it’s a mild degree such as breaking a leg, they’ll get up and walk on the leg. They feel that something is uncomfortable but they keep on moving,” she said. “For other children, the pain loss is so severe that they can injure themselves repetitively and actually mutilate themselves because they don’t know when to stop.”
All HSAN disorders are recessive genetic disorders — both parents have to carry the genetic mutation in order to pass it on to a child. But there is less than a 1-in-4 chance that the child will develop it. …
A more common HSAN condition is familial dysautonomia, or FD. There are about 500 cases of FD in the United States, Axelrod said.
The first sign of FD is a child’s inability to suck properly followed by delayed milestones — these children walk and speak later.
Often, FD patients endure severely dry eyes because they are unable to produce tears.
Also, part of this sensory disorder is difficulty “telling where they are in space,” Axelrod said.
The minor effect is constantly bumping into things. The major effect is that 80 percent of these kids suffer curvature of the spine because they have no concept of posture.