The actor/singer penned a touching tribute Monday, saying her passing has "left a hole in my heart." They were super close, which was obvious in the series of photos he shared of DeOndra and himself.

In a moving post, Jamie wrote, "Anyone who knew my sis... knew that she was a bright light... I can’t tell you how many times we have had parties at the house where she has got on the dance floor and stolen the show... even gave her boyfriend @chrisbrownofficial a run for his money."

He added, "well I know she is in heaven now dancing with her wings on...tho my pain is unbelievable I smile when I think of all of the great memories that she left me... my family... and her friends."

Back in 2018, Jamie credited DeOndra for always reminding him of what's really important in life -- "You see this girl over here, 'I just want to live. I want to dance. I want to love.' So, she brings you back down to what life is."

He said some of the fondest memories of his sister included DeOndra being named Ambassador for the Global Down Syndrome Foundation in 2011 and her dancing in his "Blame It" music video.

DeOndra was 36.