There will be a birthday party this weekend in an Ahwatukee Foothills park, but there may not be a mound of presents for Ben Stokman.

Instead, his parents asked for donations for medical research.  Ben needs a cure more than he needs toys.

Ben is battling a rare child-hood blood disease with the unfriendly name of JXG, or Juvenile Xanthogranuloma.  It has meant eight brain lesions and 10 skin lesions, 50 nights spent in the hospital, for surgeries and two trips to specialists in other states.

But the important number is 1, which Ben turned Wednesday.  This weekend's birthday party is a milestone that Bill and Carolyn Stokman feared would never arrive.

"We weren't even sure he would make it there," Carolyn said.

The little boy with the blue eyes and fuzzy blond hair keeps handling out smiles, as if nothing's wrong.  He loves to bounce balls on the tile floors, has a penchant for the telephone and remote controls, and seems to always be giggling.

"He's just smiling all the time," Bill said. "All the nurses fight over who gets Ben."

Carolyn said, "You'd never know he was sick."

And that can be both comforting and deceiving.

Diagnosed in May, Ben began chemotherapy on Mother's Day.  If chemo doesn't work, his case is potentially life threatening, said Dr. Michael Etzl, Jr., Ben's pediatric oncologist at Phoenix Children's Hospital.

"His overall prognosis is very guarded," Etzl said.

Ben's illness is part of the histiocytosis group of diseases, which range widely from benign to potentially fatal.  Histiocytosis affects approximately 1 in 200,000 children in the United States each year.

But JXG is even more rare.  Ben's brain lesions make his case more unique still, because JXG usually only affects the skin.

Ben's traveled to Johns Hopkins and Texas Children's Hospital.  Specialists from Washington University in St. Louis and the University of Pittsburgh School of Medicine to the LA Children's Hospital, and a hospital in Vienna also helped along the way.

Exactly what causes JXG isn't known.

To raise money for research and to raise awareness of histiocytosis, Carolyn's running partner, Beth Kozura, decided to organize a 5K Ben's Run.

Now an entire committee - from Carolyn's co-workers at Motorola and Bill's former co-workers at Honeywell, to friends, a neighbor, college friends and parents of children with similar conditions - meets twice a week to plan the event.  Others also are involved.

Ben's Run is Dec. 8 at Papago Park in Phoenix.  There will be a certified 5K run, plus a 5K walk, 1-mile fun run, 100-yard dash for kids and other events from a silent auction to a visit from Santa.

They hope to attract 750 to 1,000 people and raise about $40,000 through registrations, the auction, donations and sponsorships.   All proceeds will go to the Histiocytosis Association of America.

"I felt like I needed to do something to support them,"  Kozura, of Scottsdale, said of the family.  "I felt like it was a way to honor Ben."

At first, the thought was to have just a fun run to show support for Ben and the family.

"Then the realization came.  Raising money is very important.  It's an orphan disease," she said.  "It's a know disease, but they don't understand enough about it."

Bill is a consultant and hasn't worked at Honeywell for a couple years, yet people there raised $2,500 for the family.  His current employer is just as supportive.  His wife's co-workers at Motorola, where she's now on leave, were quick to help, too, as were college friends from the Purdue and Arizona State Campuses.

The gestures helped financially and freed up time so the couple could concentrate on Ben and their daughter, Marie, who's third birthday also will be celebrated this weekend in the park.   Bill and Carolyn are problem solvers, highly organized with engineering backgrounds and two master's degrees apiece.  Yet this is a problem they can't solve.  They can only wait and hope.

Parents of babies embrace a world of expectation, imaging the countless events the children will grow up to experience.  With Ben, Carolyn says, the list of exceptions is blank.

"There's nothing beyond today and next week."

Reach the reporter at chris.fiscus@arizonarepublic.com or (602) 444-7942