Story highlights Logan Stevenson's parents were married Saturday

After delaying the wedding because of his illness, they moved it up so he could be there

Logan died Monday night; he had contracted leukemia because of a genetic disorder

Logan Stevenson's role as best man at his parents' wedding Saturday came just in time.

Logan, a 2-year-old terminally ill boy whose parents moved up their ceremony so he could witness it, died Monday night at his home in Jeannette, Pennsylvania, with family at his side, Westmoreland County Deputy Coroner John Ackerman said Tuesday.

The child died of complications from the genetic disorder Fanconi anemia, Ackerman said.

On Monday, Logan's parents, Christine Swidorsky and Sean Stevenson, held him for long periods after it became apparent that his death was near, his mother wrote on Facebook.

"At 8:18 my son took his last breath in my arms," the mother, now known as Christine Swidorsky-Stevenson, wrote Monday night. "Im so sad upset and im in disbelief he is with angels and he's in no more pain. no more sickness no more hospitals."

The parents had put off their wedding for two years, hoping that Logan's health would improve.

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The wedding was set for July 2014, but after being told that Logan had just weeks to live due to leukemia brought on by the Fanconi anemia, his parents moved their wedding to Saturday.

"Under the circumstances of what the doctors told us, we just decided to go ahead and do it while he is still with us," Stevenson told CNN Pittsburgh affiliate KDKA

On Saturday, Logan, dressed in a tan suit and an orange shirt matching his mom's bouquet, looked on as his parents exchanged vows in a backyard ceremony. Swidorsky carried her son down the aisle, and his grandmother then cradled him in her arms, his favorite brown teddy bear by his side.

"This is our dream come true, all our family together, and we're all together celebrating. The celebration of my son's life and the celebration of our marriage," Swidorsky said, as Etta James' "At Last" played in the background.

Swidorsky said she often described her son as a fighter. He battled through health complications and medical treatment since birth, but remained strong.

Fanconi anemia most frequently results in death, commonly from cancer, between the ages of 25 and 30.

Funeral arrangements for Logan, who left behind two older sisters, are being made in Jeannette.