July 23, 2010 -- Six-year-old Vincent Groetzner was enjoying one of his first days of summer vacation splashing in a wading pool in his Florida neighborhood when his legs began to hurt. Then he broke out in a heavy sweat and his heart began to race.
Within hours, the young boy's vital organs had failed and he was pronounced dead despite his mother's fervent efforts to keep him alive.
Now, doctors are trying to determine whether the boy suffered from a rare hereditary disorder known as malignant hyperthermia that affects only about 1,000 people each year -- and his mother hopes finding out could help save Vincent's three siblings and other kids.
While most cases of the heredity disorder occur when a patient is undergoing surgery -- the condition is sparked by a reaction to general anesthesia -- Vincent was outside playing when he fell ill.
"Vincent's case is certainly unusual," said Dr. Henry Rosenberg, an anesthesiologist and president of the Malignant Hyperthermia Association of the United States.
Doctors like Rosenberg are beginning to research exactly what happened to Vincent and are trying to determine whether there may be other unknown causes of the disorder than previously thought.
"For many, many years, the primary focus for this syndrome has been in relation to the operating room," said Dr. Henry Rosenberg, an anesthesiologist and president of the Malignant Hyperthermia Association of the U.S.
For those patients who suffer malignant hyperthermia during surgery, there is a drug available that will reverse the condition and, in most cases, save the patient's life, said Rosenberg.
"But over the course of the past few years, we've heard more cases of patients who have developed what sounds like malignant hyperthermia not in conjunction with general anesthesia and outside of the operating room," said Rosenberg.
Vincent's mother, Lisa Groetzner, said that her son was a typical first grader before his death and said she hopes her loss helps other parents avoid the same heartbreak.
"He was awesome," Groetzner said of her son. "He was an honor roll student and was nicknamed 'the wall' because of his defensive skills playing soccer."
Boy Gets Sudden High Temperature, Racing Heartbeat
According to Groetzner, Vincent complained of a headache just before going over to a friend's house near their home in Mount Dora, Fla., on June 14. But knowing that Vincent had a habit of not wearing his glasses, Groetzner said she chalked his headache up to his eye problems.
But when Vincent arrived at her doorstep just 20 minutes after leaving with the help of her neighbor, she knew something much more serious was happening.
"I opened the door and Vincent said to me 'Mama, I don't know what's going on but I can't bend my legs. And my heart is pounding out of my chest,'" said Groetzner. "I felt his chest, and his heart was racing and then I realized how hot he felt."
Later, doctors determined that Vincent's temperature had soared to a whopping 107 degrees.
"He kept telling me on our drive to the hospital, 'Mama, I can't open my mouth,' through his little clenched teeth," said Groetzner. "And when we got to the hospital, he told me, 'Mommy, you're going to have to carry me [inside].'"
At that point Groetzner said her son had begun to foam at his mouth. Shortly thereafter, Vincent died.
While Vincent's autopsy report showed no identified evidence of malignant hyperthermia, it did show that he had "undiagnosed neuromuscular disorder."
Vincent had been diagnosed with hyperlordosis, a muscular deformation that manifests itself as an exaggerated arched back, as a toddler.
Groetzner said she had visited about half a dozen doctors to determine the cause of the deformity but had not succeeded.
Now she wonders whether Vincent's arched back may have made him more susceptible to malignant hyperthermia.
Muscular Disorders Could Predispose Patients to Malignant Hyperthermia
According to Rosenberg, Groetzner's theory might not be completely off base.
Vincent's hyperlordosis could be a "clue" to why he died, said Rosenberg.
"There is a whole spectrum of muscle disorders, and a few of those are linked to malignant hyperthermia," he said. "There is a lot more to be known, and the connection between hyperlordosis and the malignant hyperthermia has not been made yet.
Rosenberg said that parents who are concerned about malignant hyperthermia should take necessary precautions with their kids in extreme heat and also alert doctors if a family member has ever had a bad reaction to general anesthesia or suddenly died.
The tests that exist to identify malignant hyperthermia are not foolproof and are so invasive and expensive that they are not recommended for patients who are not definitely predisposed to the condition.
Groetzner hopes that Vincent's story will encourage parents to be as diligent and as pushy as they need to be to get answers out of doctors.
"If a doctor is not giving you an answer or is not being an advocate for you when in your heart you know there is something going on, you have to keep pushing," said Groetzner. "Don't ever let doctors feel like you don't know. We know our children. "
Since Vincent's death, Groetzner said she has continued to try and determine what her son's underlying disease was.
Her three other children - ages 9 months to 5 years old -- have a 50 percent chance of contracting malignant hyperthermia if that is, in fact, what caused Vincent's death.
"It makes me nervous; I'm terrified for my other children," said Groetzner.
"The only thing I can think is that this happened to Vincent so he'd save his other siblings."