It is something no parent ever wants to do - dealing with the death of a child.

But it is a desperately sad reality one Auckland couple is facing not for the first or even second time.

Claire and Stephen, who are keeping their surname private, have already lost two daughters in tragic circumstances and are now preparing for their 20-year-old son's final days, after he was diagnosed with brain cancer.

Their son, Daniel, was looking forward to heading back to study after taking a gap year break after high school.

He had his courses planned out and was all set, until a seemingly bad headache would turn all those plans upside down in a matter of days.

On June 15, he had a "raging headache" so bad that his parents called an ambulance. When paramedics arrived, they decided the young man needed to be rushed to hospital.

Family friend Leanne Manaro, who has created a Givealittle fundraising page for the family, said several tests and scans were carried out in the coming days.

When the results came back, it was heartbreaking news. A deep mass was detected on the left side of Daniel's brain and he was diagnosed with a Diffuse Midline Glioma - a fast-growing aggressive tumour.

Daniel, 20, was looking forward to heading back to study this year when he was diagnosed with aggressive brain cancer. (Photo / Givealittle)

In other words, he has brain cancer.

"On the 23rd of June, Daniel went in for surgery to remove the tumour. It was a nine-and-a-half-hour surgery," Manaro said.

'Daniel does not want much before he dies'

"They couldn't remove all of it as it had now grown down into the brain stem."

Daniel's family was also hit with the sad prognosis that he has about a 50 per cent chance of staying alive for the next six months.

He has zero chance of living to two years, the family has been told.

The young man is now in palliative care. Both his speech and eyesight are affected and he has limited use of his right-hand side.

He cannot look after himself and he is bedridden.

"Daniel does not want much before he dies," Manaro said.

"His bucket list is unassuming, just as this young man is.

"[It] includes going to the zoo with his family and friends, visiting Kelly Tarlton's, maybe go in a plane, but mainly to enjoy time with family and friends visiting the places mentioned.

"Please help. Even the smallest amount will help us give this brave young man what he deserves before his time is up."