A Porterville family says they were not allowed to board a flight coming home from a family reunion because of their son's disability.The Vanderhorst family had upgraded to first class and was just about to board the American Airline flight in New Jersey when airline security pulled them aside and told they could not get on the plane.Their 16-year-old son Bede has down syndrome. Robert Vanderhorst told 23 ABC that airline security told them that their son was a security risk because of his disability.Vanderhorst said the airline released a statement saying their son was excitable, running around, and not acclimated to the environment. Additionally, they said the pilot personally tried to calm the boy down."Asking the Vanderhorst family to take a different flight was a decision that was made with careful consideration and was based on the behavior of the teen. Our Newark customer service team, as well as the crew, worked with the family in an attempt to get Bede comfortable. Unfortunately, the crew determined he was still agitated, and at that point the Vanderhorsts were asked to take an alternate flight," said Matt Miller, American Airline spokesperson.Vanderhorst said the pilot never came over to them and at no time was their son running around, causing a disturbance. He also said their son has flown with them dozens of times in the past without any problems. They believe the only difference is, this time they upgraded to first class."I think the pilot was concerned that my son was going to be in first class and I believe the pilot felt that my type of son, my disabled down syndrome son should not be in first class," said Vanderhorst.American got them seats aboard another airline, but to add insult to injury they said, they were placed on the very back of the plane surrounded by airline personnel.The family's story has already received national attention. Vanderhorst is planning to sue the airline for how they treated their son.