'Luckiest guy in the world': Ottawa scientist races for son battling leukemia

When Emilio Alarcon's one-year-old son Alonso was diagnosed with leukemia, he quietly promised the little boy also born with Down syndrome and a hole in his heartthat someday they'dgo running together.

Today, Alarcon intends to fulfill that promise.

Alarconplans to cross the finish line at the Ottawa Race Weekend half-marathonwith the now six-year-old Alonsoin his arms.

After years of hospital visits, Alonsois now off treatment, although he's beingclosely followedby an oncologist to monitor his health.

"It's like a catharsis to me when I'm running," saidAlarcon,a researcher at the Ottawa Heart Institute. "I have a lot of memories flashing back from those days in the hospital,"

'A gift to me'

Race weekendbringstens of thousands of people to Ottawa from across the country and world. It's the largest multi-distance race in Canada.

Alarconis also raising funds for the Ottawa Heart Institute.He saidhe feels indebted to the health care system which helped save his son's life.

"The new memories of the times I spend with him and my wife [are] a giftto me," he told CBCRadio's All in A Day.

"I'm doing my science [in the best way I can] to give back to society, to give back to the community that's what I do. And I do it because of[Alonso]."

Alarconhas chronicled his son's battle with leukemia on Facebook, where he's written both heartbreaking and hopeful letters to Alonso each accompanied by a photo of the boy with a wide, excited grin.

"Three years ago, we were starting the first round of chemo, my first thoughts were that I will not get a chance to see you walking," he wrote in a post on July 2016.

"Three years after that day, you are still herebuddy, [surviving] a not-so-good prognosis."

A month later, in another post, he writes about how grateful he is for the time they've had together.

"The luckiest guy in the world was given a gift, but he did not realize what he had until one day, when he saw his son really sick and was told he might not live for [much] longer," he wrote.

"But his son was not scared or unhappy ... in those 18 months, his son taught him that true love does not count chromosomes and prognoses."

A scientist and a father

Originally from Chile, Alarcondecided to stay in Canada when his son got sick so he could be treated at theChildren's Hospital of Eastern Ontario.

Hewas eventually recruited by the Ottawa Heart Institute, where he alsomentorsstudents in his field, teaching them how to help families in similar situations.

Alarcon said that being both a scientist and a parent of a child with serious health issuestaught him a lot about health care.

"You start realizing we have the conception that modern medicine can cure everything. But there are a lot of pitfalls in there," he said.

Alarcon said he'd be wearinga necklace made of handcrafted beads, adorned with black letters spelling out the names of his wife and his son, during Sunday's race.

He also prepared for the race by mapping out a training route in Barrhaven in the shape of a heart an ode, he said, to why he runs.