Angie Rush(ATLANTA) -- Three young brothers are all sharing the same fight after being diagnosed with eye cancer.

Tristen, 5; Caison, 3; and Carter Rush, 7 months, are being treated for retinoblastoma.

Tristen received his diagnosis in April 2014. Caison was diagnosed in October 2016 and Carter in January of this year.

"It was surprising, but we knew that the chances were 50/50," mother Angie Rush of Atlanta told ABC News' Good Morning America. "I had been told by doctors most of my life that because of the genetic mutation with the retinoblastoma that I have in both eyes I had a 50/50 chance of passing it on."

Rush said she too was diagnosed with retinoblastoma at just 6 weeks old, but is healthy today.

Her boys are receiving chemotherapy once a month, along with eye checks and laser treatments.

Dr. Thomas Olson, director of the solid tumor program at the Aflac Cancer and Blood Disorders Center of Children’s Healthcare of Atlanta, confirmed the cancer the brothers have is hereditary.

"That being said, it is very rare for all three of the children to be diagnosed," Olson told GMA. "It’s a risk when you have familial bilateral retinoblastoma."

"Because mom had retinoblastoma, the babies were checked at birth," he added. "Even though Carter was not diagnosed until 6 months old, he was being screened since birth. Pediatricians check for a certain type of reflex in the eye. Anytime there's something abnormal in the eye, the child should be seen by an ophthalmologist."

Despite their health struggles, Rush said her sons are typical, happy kids.

"They get along great but they're still brothers -- they have a lot of energy," she said. "Tristen is so friendly and loves to sing. He loves science ... we're kind of hoping he'll be a doctor someday."

"Caison is a bit shy, but has great personality and makes us laugh a lot. Carter's personality is still growing, but he smiles at everybody," she added.

Because of the costly medical bills, Rush, her husband Aaron and their kids had to sell their home and are living with relatives.

Strangers across the country have since been donating to a crowdfunding page to help the family get back on their feet.

"The encouragement, people saying they're thinking of us, it's been wonderful," Rush said, adding how thankful she is. "The monetary support has been wonderful, too."

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