When you first meet 4-year-old Roberto Salazar, you can't help but notice his unwavering smile and constant laughter. By all accounts, he's a very happy boy.
It is only when he rams his head violently into walls or plays a little too roughly with a schoolmate, all the while smiling, that you are reminded that he suffers from an incredibly rare genetic disorder.
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.
Roberto was born in July 2001, becoming Luis' and Juan's little brother. As a newborn, his parents thought he was the perfect baby.
"Roberto was wonderful. He never cried. He would sleep 23 out of 24 hours a day. He never cried to eat, never cried that his diaper is itching," said his mother, Susan Stingley-Salazar.
At 3 months, things abruptly changed. Roberto refused to eat. He was rapidly losing weight. His parents tried desperately to find ways to "force a child to eat that doesn't want to eat," Stingley-Salazar said.
First they tried to feed him with an eyedropper. Then a feeding tube was attached to his stomach at 8 months.
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.
"If you could imagine when you bite your tongue how bad it hurts. At one point, you couldn't even distinguish that his tongue was his tongue," Stingley-Salazar said.
Stingley-Salazar, a registered nurse with a degree in molecular biology, took Roberto to see more than 60 physicians in the boy's first few years. She researched his symptoms on the Internet every night. She e-mailed any specialist she could find.
She came up with very few answers until she contacted Dr. Felicia Axelrod of the New York University Dysautonomia Treatment and Evaluation Center.
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.http://www.cnn.com/2006/HEALTH/conditions/01/27/rare.conditions/index.html?section=cnn_latest