The 7-year-old, born with Schimke Immuno Osseous Dysplasia -- a rare form of dwarfism -- died at Hackensack University Medical Center around 8:35 p.m. on Thursday, Nov. 21.
"He fought," said his mom, Rezarta Osmani, "he fought so hard every last minute."
Last month, Osmani donated her kidney to Leart. But the organ needed to removed in less than 12 hours and the boy required more surgeries.
He under went several more surgeries in the last three weeks, later developing pneumonia and multiple other infections.
Despite his will to live, the complications took Leart's life.
A GoFundMe was launched in June 2018 to help get Leart a dog. Osmani plans on donating remaining funds to the Kruzn For A Kure Foundation, which aids families of children with the same condition as Leart "so that other mothers don’t have to suffer like I do," Osmani said.
Condolences poured in.
"Leart was truly special and was so lucky to have such a strong warrior mom willing to do whatever it took for him," Carolyn Zimmerman said.
"You have such a beautiful family and it was an honor to know you. Leart is watching over you, standing tall with his ps5 and no longer suffering. God bless ❤️"
"My heart is broken for you guys, it was an honor to know and take care of Leart over the past few years," Stacey Lynn wrote added.
"He is one of the strongest kids I've ever met with the biggest personality."
A police officer who was close with Leart will escort his family to the burial on Friday, Nov. 22 at Laurel Grove Cemetery in Garfield.
Leart is survived by his mom, Rezarta Osmani, father Arton Dervishaj, and brothers, Endi, 4, and Tian, 18 months.
Click here to follow Daily Voice Cresskill-Closter and receive free news updates.