*”Good Morning America” co-anchor Robin Roberts announced this morning that she’ll begin medical leave to undergo a bone marrow transplant at the end of this week.


Roberts, 51, said on-air that her last day before an extended absence will be Friday. She plans to check into the hospital next Tuesday to begin preparing for the transplant, which will take place several days later. Her sister Sally-Ann Roberts will be the donor.

In June, Roberts, a breast cancer survivor, announced that she had been diagnosed with myelodysplastic syndrome (also known as preleukemia), a blood and bone marrow disease.

Throughout the week, “Good Morning America” will air segments celebrating “Robin’s Journey.”

ABC’s Diane Sawyer, Katie Couric and Barbara Walters are among the talents who will pinch hit for Roberts during her absence. Roberts plans to return to “GMA” after her recovery, though a specific date has not been set.