Mary Dempsey and Patrick Dempsey attend the Hope Honors in 2008.Photo:Jamie McCarthy/WireImage

Mary Dempsey and Patrick Dempsey attend the Hope Honors hosted by the Avon Foundation at Cipriani 42nd Street on October 28, 2008 in New York City.

Jamie McCarthy/WireImage

MeetPatrick Dempsey’s older siblings.

TheGrey’s Anatomyalum is the youngest child and only son ofWilliam and Amanda Dempsey, who were also parents to daughters Mary and Alicia Dempsey.

In contrast to their high-profile actor brother (who was recently named PEOPLE’s “Sexiest Man Alive” for 2023), his sisters live much more private lives.

However, the siblings' professional lives have crossed in another way. While neither Mary nor Alicia are actors or racecar drivers, they’veteamed up with Patrick on a familial pursuitin honor of their late mom Amanda, who was diagnosed with cancer in 1997 and died in 2014.

Together, they co-foundedThe Dempsey Center, a non-profit cancer support center established in 2008. Patrick, Mary and Alicia have hosted public events and fundraisers over the years in support of the organization and in tribute of their family name.

He explained how his sister was “very much on the front line with the doctors,” and worked “to keep my mom active with projects around the house,” like remodeling and restoring old homes. Patrick said she would always find ways “to keep positive” and “get her out of bed in the morning.”

Read on to learn more about Patrick’s sisters, Mary and Alicia.

Mary Dempsey

Jillian Dempsey, Patrick Dempsey, and Mary Dempsey.Dimitrios Kambouris/WireImage

Gillian Dempsey, Patrick Dempsey, and Mary Dempsey attend the Hope Honors hosted by the Avon Foundation at Cipriani 42nd Street on October 28, 2008 in New York City.

Dimitrios Kambouris/WireImage

Mary Dempsey is Patrick’s sister and the middle of the Dempsey siblings. She grew up alongside her brother and sister in Buckfield, Maine.

Along with Patrick, she is co-founder of The Dempsey Center, a nonprofit cancer support center established in 2008 to honor their mother Amanda Dempsey who passed away in 2014 at age 79.

After 10 years of service, Marystepped awayfrom The Dempsey Center when it formally separated from Central Maine Healthcare in 2018 to become its own nonprofit, also adding a second location.

Mary Dempsey and Patrick Dempsey attend the Hope Honors in 2008.Jamie McCarthy/WireImage

Mary Dempsey and Patrick Dempsey attend the Hope Honors hosted by the Avon Foundation at Cipriani 42nd Street on October 28, 2008 in New York City.

Less than six months later, she continued similar efforts and took onan executive roleat the Cancer Resource Center of Western Maine in Norway.

“My heart will always be with The Dempsey Center because that’s what I helped create for our mom, but I also have room in my heart for another center here in Western Maine and I’m really thrilled about being here,” Mary said, reported theSun Journal.

In May 2015, Mary received anhonorary doctor of public service degreefrom Saint Joseph’s College at the school’s 102nd commencement ceremony. In additionto her work in med, Mary is certified in reiki and works as a laughter yoga instructor.

“Life is all about making a difference, giving back, being kind, and don’t forget to breathe and laugh along the way,” Mary’sLinkedInbio reads. “Make each day count, everyday is a gift.”

Alicia Hatten

Patrick Dempsey with his mother, Amanda.Sun Journal, Amber Waterman/AP Photo

Patrick Dempsey prepares to start the Survivor Walk with his mother, Amanda on Oct. 8, 2011, in Lewiston, Maine, on the first day of the Dempsey Challenge

Sun Journal, Amber Waterman/AP Photo

Alicia Hatten (not pictured) is Patrick Dempsey’s eldest sister. She also grew up in Buckfield alongside her brother and younger sister Mary, andresides in Floridanow.

In comparison to her siblings, details about her personal life remain more private. However, she’s been involved in The Dempsey Center alongside Patrick and Mary, in 2014joining them onsite to dedicate a flower garden to the center in their mother’s honor.

In 2020, she opened up about the Amanda Dempsey Award, an honor that has been included in “The Dempsey Challenge,” an initiative created to benefit the Center.

“It’s a way of paying tribute to our mom and also it’s a way of keeping her memory alive," Alicia said during thevirtual awards presentationvia Zoom.

Alicia was photographed alongside her mom, Mary, at the Dempsey Challenge in 2011. The two werepictured looking at each other and smilingas they carried a banner filled with signatures.

Another photo captured Alicia at The Dempsey Challenge in 2014. She waspictured holding a microphone alongside Patrickwhile they both smiled on stage.

source: people.com