Dane -- who shot to fame amid six seasons on the hit ABC drama "Grey's Anatomy," where he played Dr. Mark Sloan, affectionately known as "McSteamy" -- said his symptoms began over one year ago, when he began to experience weakness in his right hand.

Eric Dane is sharing a candid update on his battle with ALS. The 52-year-old actor sat down with Diane Sawyer for a Good Morning America interview, which aired on Monday, June 16, where he explained the early signs of his condition and the difficult path to diagnosis.

Actor Eric Dane opened up about his battle with ALS. In a heartbreaking interview, he grew emotional while discussing his diagnosis, revealing that one of his arms has completely stopped functioning.