Landon Jones, 12, lost his appetite and sense of thirst overnight. On October 14, last year he woke up with no desire to eat or drink.

Once energetic youngster stopped running, cycling and playing with friends.

Doctors at five different hospitals have failed to discover what is wrong.His parents Michael and Debbie are desperate for a diagnosis and treatment.But test after test has failed to offer any hope of answers to their questions.Experts believe Landon's may be the only case of its kind in the world. 

Today Landon's parents Michael and Debbie are at their wits end, desperate for help to discover what is wrong with their son.

And Mr and Mrs Jones took their son to Rochester in Minnesota where experts at the world-renowned Mayo Clinic examined Landon's case.

But their frustrating search has, so far, produced no answers.
 
The National Institutes of Health in the US is now considering offering Landon an appointment - they only examine the rarest of cases each year.

In the last year Landon has shed almost 36lbs, plummeting from 104lbs to 68lbs, after he started to lose around 2lbs a week last autumn.

Mr and Mrs Jones have tried everything they can think of to encourage their son to eat.

But the 12-year-old rarely eats more than a bite of his sandwich at lunch and a few crisps.

Experts at the Mayo Clinic in Rochester say they believe Landon's may be the first case of its kind in the world

Experts at the Mayo Clinic in Rochester say they believe Landon's may be the first case of its kind in the world

While his younger brother Bryce, nine, bounds in from school each day to play with the family's dog, lethargic Landon prefers to lie on the sofa.

In the last year he has missed 65 days of school.

And his parents say he hasn't run for months, forced to watch his classmates from the sidelines.

Repeatedly Landon's parents urge him to take a bite to eat, take a drink.

The next step, they say, is to insert a feeding tube, to help nourish Landon directly through his stomach.

Mr Jones said they believe their son's illness is linked to the hypothalamus in Landon's brain, malfunctioning.

The size of a flattened pea, it regulates hunger and thirst as well as body temperature, blood pressure and sleep cycles.

Dr Marc Patterson, a child neurologist at the Mayo Clinic, said Landon's may be the only case of its kind in the world.

Mr Jones said another possible cause of Landon's illness is treatment he received three years ago for absence seizures. 

The then nine-year-old would sit and stare into the distance, oblivious to the world around him.

Doctors prescribed him Depakote, commonly used to treat such seizures, and was on the drug for a year.

The family doctor has now questioned whether there is a link between the drug and the suppression of Landon's appetite.

But Dr Patterson said the drug is typically linked to increased hunger and weight gain.
Now Mr and Mrs Jones' plea is simple, they are appealing for anyone who can help to get in contact.