Dáithí Mac Gabhann will have surgery in England on Thursday which his family hope will get him back on the heart transplant waiting list.
The six-year-old was “temporarily suspended” from the list last month due to his health.
He will undergo a cardiac catheter in Newcastle.
“We have a date for Dáithí’s surgery,” his fundraising page tweeted.
“Dáithí will travel to Newcastle on Wednesday and undergo a cardiac catheter on Thursday, which will hopefully get him back active on the heart transplant waiting list.
“All positive thoughts and prayers welcome.”
Dáithí was awarded the freedom of Belfast at the start of June after his family’s campaign to bring in opt-out organ donation in Northern Ireland.
The law is known as Dáithí’s law.
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