Harvey was three days old when he died in his dad's arms of an extremely rare disease. Now his grieving family are fighting to save his little brother from the same grim fate

The family of a toddler battling a rare medical condition that saw his older brother die in his father's ams at just three-days-old desperately require a life-saving transplant to save him from the same grim fate. 

Hunter Fletcher, who will turn one next week, urgently needs a liver transplant after he was diagnosed with the same rare genetic disorder as his late brother Harvey. 

The 11-month-old boy has OTCD (ornithine transcarbamylase deficiency), a disorder which causes an excessive build up of ammonia inside the body. 

Hunter's father Peter told Daily Mail Australia his son is doing well considering the circumstance but that they were struggling to find a donor. 

'He needs ongoing and constant care while we're waiting for a liver,' he said. 

'We haven't (had anyone) contact us for a liver.'

Ammonia is a type of waste that is usually processed through the liver, however if it builds up it can affect a persons central nervous system. High levels of the toxic chemical can cause unconsciousness and even death. 

The family, who live in Berri northeast of Adelaide, can only give Hunter small amounts of protein and give him meals through feeding tubes. 

Mr Fletcher said he made the call to give his liver for his son and had even given up drinking so that he could go through with the procedure. 

'I wanted to be the donor and went sober for 6 (sic) months but I found out I was the wrong blood type,' Mr Fletcher said. 

Hunter who was diagnosed with C.C717G>T -  a very rare variant of the OTCD that his specialists had never seen before. 

'His case is the only variant that they have ever seen so far,' his father said. 

'It is very rare... Doctors see maybe 1 to 2 (sic) cases a year.'

Hunter's mother Caitlyn Kourasanis told 7 News she is hoping the family will find the right donor to give her son a shot at life. 

'It's the not knowing. The phone could ring in the middle of the night. When I get a call from an unknown number, you wonder if it's the one,' Ms Kourasanis said.

She says she is hopeful a donor can be found before Christmas. 

The family lost their son Harvey to the same condition when he died in Peter's arms aged just three days old from the devastating illness two years ago.  

According to the latest government figures, liver transplants from deceased donors made up the second largest type of organ transplant that was required.

There was a three per cent increase in liver transplants between 2021-2022 however in South Australia, the number of deceased organ donors who could have provided  liver transplants, decreased from 29 to 20 during the same period. 

The Fletcher family will be spending Christmas at the Ronald McDonald House (RMHC) in Adelaide, a community service they have used since Hunter was born. 

RMHC provides services to the families of children living with serious medical conditions.