(NEW YORK) -- Robin Roberts will make her final appearance on ABC's Good Morning America Thursday before she begins an extended medical leave to begin treatment for MDS, a rare blood disorder that affects the bone marrow.
Roberts had initially announced that Friday would be her last appearance, but changed plans upon news that her mother, Lucimarian Roberts, had fallen gravely ill. Roberts will now travel to Mississippi to be at her ailing mother's side before beginning her own treatment, which will include a bone marrow transplant to be donated by her sister, Sally-Ann Roberts.
On Thursday, Martina McBride is set to perform "I'm Gonna Love You Through It" on GMA in honor of Roberts, who also is a breast cancer survivor and who appeared in Martina's video for "I'm Gonna Love You Through It" last year. Martina says of Roberts, "She is an inspiration to me, my family and my fans. I can't wait to see her on Thursday to give her a big hug and perform for her. It's an honor."
Roberts revealed her MDS diagnosis on Good Morning America last June, and how she underwent a procedure to extract bone marrow on the day before she was to interview President Obama. That interview grabbed headlines when the president used it to announce his support of gay marriage.
"The combination of landing the biggest interview of my career and having a drill in my back reminds me that God only gives us what we can handle and that it helps to have a good sense of humor when we run smack into the absurdity of life," said Roberts.
Copyright 2012 ABC News Radio