Keenan Cahill, Beloved YouTube Star Famous for His Lip-Synching, Dead at 27

Keenan Cahill, the YouTube star famous for lip-synching and celebrity cameos, is dead. He was 27.

At age one, Cahill was diagnosed with Maroteaux Lamy Syndrome which is a "progressive condition that causes many tissues and organs to enlarge, become inflamed or scarred, and eventually waste away (atrophy)," according to the National Library of Medicine. Skeletal abnormalities also commonly occur with this condition.

The star announced on his social media earlier this month that he was having open heart surgery on Dec 15. His family said on a GoFundMe set up in the wake of his death, that he was recovering from the surgery when he developed complications and died Thursday.

Rachel Murray/Getty Keenan Cahill

"We are devasted to announce that our nephew, Keenan Cahill, passed away on December 29th at the age of 27. Twelve days earlier he had open heart surgery and was starting to recover, but complications arose that he couldn't overcome," his aunt wrote on the GoFundMe.

Cahill, frequently cited as one of the original YouTube stars, first rose to fame in 2010 when he started uploading videos of himself lip-syncing current hit songs.

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He eventually caught the attention of many celebrities who would make cameos in his videos. Some of his famous guests were Jennifer Aniston, Katy Perry, and 50 Cent, according to WGN-TV in Chicago which first reported news of his death.

His YouTube channel has amassed more than 500 million views and has more than 720,000 subscribers.

Celebrities and fans turned to social media to share their memories of the star.

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Jersey Shore alum Pauly D shared a tribute to Cahill, whom he worked with previously, on Twitter.

"Rip Keenan Thank You for always making the world smile," he wrote alongside a photo of the two performing together.

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According to this family, "he never made a lot of money, but he enjoyed what he was doing and brought smiles to the faces of so many people."

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"Thank you to everyone that made Keenan's short life memorable. He will be missed by all who knew him," his aunt wrote/