"EXTREME MAKEOVER: HOME EDITION" LENDS A HELPING HAND TO A BIGHEARTED FAMILY WHO LOOKED BEYOND THEIR OWN MEDICAL AND FINANCIAL STRUGGLES TO RALLY THEIR COMMUNITY FOR LEUKEMIA AWARENESS

Patrick Dempsey Volunteers as Part of "Get on the Bus" Campaign

"Marshall family" -- "Extreme Makeover: Home Edition" travels to Lyme, NH -- with a special appearance by Patrick Dempsey, plus a Hollywood blockbuster movie star -- to tell Jay and Elena Marshall that their moldy and rotting home will be rebuilt in seven days. This episode of "Extreme Makeover: Home Edition" will air SUNDAY, NOVEMBER 29 (8:00-9:00 p.m., ET) on ABC.

Six years ago, Jay and Elena Marshall bought the perfect home, one that they could live in forever because they could easily expand as their family grew. But before they had a chance to build their first addition, an onslaught of problems from carbon monoxide leaks to mold and rotting wood brought their dreams for the home to a halt. Before they could begin tackling the growing list of problems, their nine-year-old son, Cameron, was diagnosed with leukemia. Despite the mounting medical bills and the fear of having to leave their home due to the dangers it presents to Cameron's recovery, the Marshall family came together and rallied their community behind their son's "Be Positive" campaign. The "Be Positive" campaign, named after Cameron's blood type, has already brought in around $40,000 for the Children's Hospital at Dartmouth and leukemia awareness, including $3,500 Cameron raised on his own. Now it's up to Ty and the designers to build Jay, 39, Elena, 40, Beau, 17, Olivia, 14, Kennedy, 11, Cameron, 9, Emilie, 8, Faith, 6, Rylie, 5 and Nina, 3, a safe and healthy home that will allow their family to continue to grow and the "Be Positive" campaign to flourish.

While "Extreme Makeover: Home Edition" team leader Ty Pennington, designers Michael Moloney, Paige Hemmis and Eduardo Xol transform the Marshalls' new home, the family also gets to meet Patrick Dempsey ("Grey's Anatomy" is the family's favorite drama series), plus a blockbuster comedic star will deliver a special surprise gift and video check-in for the family to welcome them to their new home.

"Extreme Makeover: Home Edition" is produced by Endemol USA, a division of Endemol Holding. It is executive-produced by Anthony Dominici. David Goldberg is Chairman, Endemol North America. The series is broadcast with Spanish subtitles via secondary closed captioning. This program carries a TV-PG parental guideline.

For more information on "Extreme Makeover: Home Edition," visit ABC.com