When the boy stepped on the scale Wednesday, the number flashed a tiny victory: 67 pounds, 9 ounces. For that rare moment, the father didn't feel like he was failing his oldest son. Landon Jones had gained five ounces.
At a cramped, one-story house in Cedar Falls, Iowa, daily life is indeed measured in ounces. And the full weight of the future seems to teeter on whether Mike and Debbie Jones can somehow prevent their 12-year-old son, Landon, from wasting away any further.
During the past 13 months, Landon has rapidly dwindled from a dancing, laughing, 104-pound dynamo to an emotionless, hollowed-out wisp of that once-vigorous kid, who lately is losing about a pound a week. The cause: a mystery. The cure: unknown. But something abruptly changed in Landon during just one night.
On Oct. 14, 2013, he went to sleep after enjoying a bowl of ice cream and a kiss from his parents. He awoke without any appetite or any thirst -- with an ill feeling that all food and all drinks, even water, were abhorrent. That sensation has never vanished, befuddling doctors at the Mayo Clinic who acknowledge they've never seen a patient like Landon.
"When we were told that he might be the only one in the world like this, it literally knocked the air out of us," said Mike Jones, a dad whose voice carries an edge of urgency. He devotes each day not to paid employment but to two primary quests, scouring the Internet for any answers and pleading with his son to take just a nibble of sandwich or sip of water.
The parents' coaxing is as grueling as their year-long hunt for medical clues. When Landon balked at downing even past favorites like french fries or hamburgers, his dad and mom gave him high-calorie nutritional shakes. Those may have helped Landon add those five recent ounces. But he's now sick of the concoctions and isn't drinking them, Mike Jones said.
"When he goes to school, I tell him, 'Always have mom's and dad’s voice in your head -- take a bite, take a drink,' " Jones said. "But as soon as I pick him up from school, I check his lunch box immediately to see how much he ate, and I know it's not going to be anything. He won’t do it, unless I tell him."
Landon's teacher, meanwhile, has offered to let the sixth-grader keep a water bottle on his desk, even agreeing to use hand signals to quietly remind the boy to sip. But when his father gave him a bottle for the classroom, Landon stashed it in his locker, untouched.
"There’s no other kids with water bottles," Landon told his dad. "And if they end up seeing it, they’re going to know about me. I don't want anybody to know about this."
Landon’s Mysterious Loss of Hunger and ThirstPlay Video - 0:37
Landon’s Mysterious Loss of Hunger and ThirstPlay Video - 0:37
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After 10 trips to the Mayo Clinic to have Landon checked by top doctors, the family is certain this isn't a psychiatric-based eating disorder. Spinal taps and stool analyses conducted by doctors also ruled out rare infections or viruses.
But the root of problem does seem to lie in his brain, agree Landon's parents and one of the specialists who examined him.
Dr. Marc Patterson, a child neurologist at the Mayo Clinic in Rochester, Minnesota, suspects Landon may have "dysfunction" in his hypothalamus, a small, deep portion of the brain responsible for controlling appetite, thirst, heart rate and blood pressure, sleep cycles, and body temperature.
Children with hypothalamus tumors, for example, can lose weight dramatically with or without loss of appetite. Brain imaging can easily spot a mass in that area. And while scans of Landon's brain seem to appear normal, he may have minuscule damage causing major problems, Patterson said.
"You could have microscopic lesions," Patterson said. "We have a reason to think this could be the source of his problems. Although the tests we’ve done have all been negative, we can’t rule out the possibility that there is some microscopic injury in the structure that we simply can’t see or detect with the tools we’ve got."
If there is damage, how did it get there?
Jones points to an anti-seizure drug called Depakote. Landon was taking the medication when he became ill. He was administered Depakote (or valproric acid) to control his "absence seizures," short spells in which people are known to stare off and blank out, his father said.
During the early stages of his medical research, Jones learned that valproric acid use by pregnant women has been associated with neurologic birth defects in the spine and brain. He believes that is a clear link. Mayo Clinic diagnostic records for Landon, shared with NBC News by the family, also list "possible toxic effect of valpropric acid."
But Patterson said he made that notation only because "it was something that the family was concerned about. I think it's hard to substantiate that." His doubts about Depakote as the cause are fueled by the overnight onset of symptoms and the fact that they arrived long after Landon started taking the drug. In addition, his appetite and thirst weren't revived when he was weaned off the medication. Finally, Depakote is commonly known to spur hunger and weight gain, he added.
What's not up for debate: the rare nature of the boy's illness.
"If people lose their appetite and won’t eat, that’s not uncommon. But to lose appetite and thirst together is very unusual," Patterson said. "The combination in Landon is one I haven’t encountered before.
"I haven’t been able to find an identical case in looking at the literature," Patterson said. "And I’ve consulted with many colleagues and we have not been able to identify anyone exactly like Landon."
His case is so unique, in fact, Jones has applied for Landon to be accepted into the Undiagnosed Diseases Program (UDP) at the National Institutes of Health in Bethesda, Maryland. The UDP defines a rare disease as an ailment with "a prevalence of fewer than 200,000 affected individuals in the United States." The waiting list for admission spans two to six months.
Eight months after applying, there has been no final answer from the NIH, Jones said.
"We do not provide information on the status of applications," Raymond MacDougall, an NIH spokesman, wrote in an email to NBC News.
The lack of response has frustrated the Jones family for two critical reasons.
"My son’s dying," Mike Jones said.
The family also has run low on money and their health insurance has been exhausted after its 13-month ordeal, Jones said. The NIH is viewed by the family as "the only door we have left open."
And to buy Landon more time, doctors have recommended that he undergo a gastrostomy -- the creation of an artificial, external opening in the stomach through which a person can receive liquid nutrition and water. Landon has an doctor's appointment Thursday to discuss the procedure.
"That's a means by which his growth and healthy nutrition could be maintained indefinitely," Patterson said. "Since we don't really know the mechanism for this, we can't say whether it would be required in the long term."
But buried in the mystery of an overnight illness that has lasted more than a year, there may be hope. Perhaps, inside Landon, an undetected genetic switch was turned on last October, Patterson wonders. And perhaps there may be as abrupt a shutoff.
"This very sudden onset is very curious in someone who is otherwise well," Patterson said. "Because this came on suddenly, it's possible that it could improve just as suddenly. It would be a happy twist."