Robin, 51, expects to undergo a bone marrow transplant this fall with her sister as a donor. She learned of the diagnosis last month.
“My doctors tell me I’m going to beat this – and I know it’s true,” she said in the statement.
ABC’s medical correspondent, Dr. Richard Besser, said in a statement that he was consulting with Robin about MDS, a rare malignant disorder of the bone marrow that typically affects elderly people and can sometimes be the result of cancer treatment.
He said her treatment would begin on Monday, when she receives a drug to prepare her for the bone marrow transplant. She will continue hosting GMA but is expected to stay off the air for several months after the transplant to recover.