Chris Johnson announces ALS diagnosis in 'Good Morning America' appearance

Former Tennessee Titans running back Chris Johnson announced he has been diagnosed with ALS (Lou Gehrig's disease) during a Monday, June 29 appearance on ABC's 'Good Morning America.' Johnson, who was diagnosed last year at age 39, revealed the news in an interview with host Michael Strahan. He stated there is no family history of ALS and that his doctors believe he has sporadic ALS, which accounts for the vast majority of ALS cases.