Published: Nov 30, 2010 12:57 AM EST
Updated: Nov 29, 2010 7:11 PM EST

LEE COUNTY, Fla. - Ft. Myers mother Debbie Umphries knows just how quickly her son can vanish.  It happened once before.

"My husband was getting ready to take [Tim] to the playground," Umphries said. "He heard the word 'playground' and was gone."

It happened in the blink of an eye.  When his father's back was turned, Tim left the house.  After a frantic search, police found the 11-year-old at his neighborhood playground.

Umphries says it was the most frightening half hour in her life. 

For Sheila Medlam, a similar 17 minutes will always haunt her.  That's how long her 5-year-old son, Mason, was missing from their Colwich, Kansas, home earlier this year.  With law enforcement combing the area, Medlam was the one to find her son floating in a nearby pond.  

Mason died in a hospital a few days later.

"We want to know that first responders have all the information they need so another mother doesn't have to lose her child like I had to lose mine," Medlam told WINK News during a recent trip to Pensacola, Florida.

In Pensacola, Medlam has found an ally in her efforts to create a nationwide alert system for missing children with disabilities.  An officer within the city's police department helped create the "Take Me Home" program for children with autism.  It's a registry that can help locate and identify a missing child with autism, currently available to numerous law enforcement agencies across the country.

[A link to more information on the "Take Me Home" program can be found at the bottom of this article, along with information on the Mason Allen Medlam Foundation.]

Medlam reached out to the program's developer with suggestions she felt would improve the registry and better aid in the search for missing children with a cognitive disorder.

The Mason Alert would:

* Quickly notify law enforcement and the community a special needs child was missing, including a picture.

* Not require proof of abduction, as is required for the well-known "Amber Alert."

* List the missing child's fascinations, such as railroad tracks - or, in Mason's case, water.

* Provide maps and locations of the nearby dangers most likely to attract the child.

* Specify if the child is verbal or non-verbal, and prepare search teams for how to best approach and communicate with the child.

Sheila Medlam believes her son could have been saved if these measures had been in place.  Although she was able to tell law enforcement of Mason's fascination with water, officers weren't aware of the pond less than 200 yards from the Medlam's front door.

"Your brain just doesn't work when you call 911," Medlam said.  "You're so terrified about what you'll find at the end of your road that you just can't think. I've never heard anyone more terrified than myself when I listen to my own 911 call."

"This is just a huge step," she said of the Take Me Home program incorporating her suggestions. "It actually legitimizes everything we are working on. It gives us a software program and a powerful tool to bring our children back to us alive."

A full-fledged nationwide alert system is still in the works, with Medlam gaining support among many non-profit organizations.  According to the National Autism Association, 92% of parents with an autistic child report the child wandering away from supervision.  Many special needs children also fail to realize the danger of their surroundings, the association says.

Especially unique to the Mason Alert would be the ability to register special needs adults.  Because developmental disabilities are often life-long, the Mason Alert would be the only alert system to currently cover any adult between the age of 18 and 64.

Parents like Debbie Umphries say they'd support it whole-heartedly.

"I think it would be a Godsend," Umphries said, Tim sitting next to her. "And I probably have 300 people in my support group that would be on board with it also."

To learn more about the Mason Allen Medlam Foundation and the Mason Alert, click here: http://masonallenmedlamfoundation.com/

To learn more about the Take Me Home program, click here: http://www.autism-society.org/site/PageServer?pagename=research_safeandsound_takemehome