The Oscar-winning actor confirmed the news of his sister’s death in an Instagram post on Monday saying that his "heart is shattered" as he paid a moving tribute to 36-year-old DeOndra Dixon.
Foxx wrote, "My heart is shattered into a million pieces... my beautiful loving sister Deondra has transitioned...I say transitioned because she will always be alive... anyone who knew my sis... knew that she was a bright light..."
He went on to describe how Dixon loved to dance and had even taken to the stage at the Grammys with him one year.
Dixon, who was born with Down syndrome, is reported to have died on 19 October.
In 2011 Foxx was quoted as saying in an interview with PEOPLE , "One thing people may not understand is that the person with special needs, the love that they give you is unfiltered. There is nothing in the way of them loving you and there is nothing in the way of them being upset with you either."
Dixon was also a global ambassador for the Global Down Syndrome Foundation, which also took to Instagram to pay tribute to a "true angel looking down on us." Their post read : Devastated for DeOndra's family, devastated for our community, devastated at Global. She will ALWAYS be remembered. Read Global's loving tribute to DeOndra with the link in our bio."