It's a very rare disease. Only about a hundred children in the valley have it. It's called Prader-Willi Syndrome. But for the kids that do have it, life can be very difficult.
We have one family's story.
It looks like playtime for 7-month-old Ben Pulcrpek. For his parents Adrian and Kristy, this is a physical therapy session for their son.
Baby Ben has a rare genetic disorder called Prader-Willi.
"I never heard of it before, we thought we were having a perfectly healthy child," says Kristy.
She did a lot of research. Her oldest son started crawling at 7 months. But Ben doesn't have enough muscle mass yet because of the disorder.
His parents Kristy and Adrian are helping him with that problem.
Little Ben gets a growth hormone shot every night to help him grow strong.
He will need the help. Prader-Willi can cause physical, mental, and behavioral problems. And it doesn't get better as they get older.
"The main symptom as an adult is they have an insatiable hunger. They always feel hungry. They can consume 10,000 calories and still feel hungry," says Kristy.
There is no cure for Prader-Willi yet, but Kristy is hoping with time and money there will be a cure soon.
There is a walk Saturday morning at 8 a.m. in Chandler at Desert Breeze Park.
They are hoping to raise money to find a cure.