Wellington toddler's mystery death caused by rare gene

Tiana was the type of child who brought everyone together, her mum said. Photo / Supplied

A Wellington toddler who unexpectedly died after simply showing signs of being tired had a rare gene that appears to have caused her death.

Tiana Milosia Waipuna-a-rangi Odell-Petueli-Kirifi was nearly 2 years old when she suddenly died in March.

Her family had taken her to the doctor, noticing she seemed slightly under the weather. Shortly after her heart "just stopped beating on its own", said mother Samantha Odell.

Tiana's loved ones have been searching for answers since the death and appear to now have them after receiving blood test results back from the United States.

"She had a very rare gene," Odell told the Herald today.

The LPIN1 gene was so rare there was not a proper name for it, she said.

Dad Tulo Kirifi Petueli said Tiana made everyone happy. Photo / Supplied

"Very little research has been done on it. If I'm correct, it has something to do with the deterioration of the muscles."

Tiana's parents are now testing their own blood to see where there gene came from.

"In order for her to get the gene, both me and her father must carry it or it was a mutation."

It's believed an infection or cold may have triggered the gene, causing the muscle deterioration.

"We took her to the hospital in the morning around 9am and from there her body just started to give up. In the end, her heart just stopped beating on its own."

Odell has been waiting for months for answers after sending Tiana's blood to a lab in Wisconsin. Now she will continue to wait to find out where the gene originated.

Today she was feeling "numb" and said the news was "hard to accept".

"Sadly I still think she is coming home," she said.

Mother Samantha Odell said Tiana was a "perfect baby". Photo / Facebook

The whole ordeal happened over just a few hours - Tiana was taken to the doctor for some blood tests, and then she died.

She was Odell's only child, and it is the second tragedy she has faced in a short time, having lost a baby during pregnancy last September.

Tiana was "a very happy child".

"She was the most easiest baby, she was full of life, always on her feet."

Odell described her daughter as "a lot older for her age".

"She was very on to it ... she was a perfect baby. Healthy as anything, no problems."

Tiana made everyone happy and was the type of child who never stayed still, "always climbing things and running around", said her father, Tulo Kirifi-Petueli.

"She didn't live her whole but lived her life while she had it," he said.

Odell said Tiana lit up the room with her smile and laugh, and used to make friends with random people.

"She was the sort of child that brought everyone together."

Tiana was always dancing, her mother said. Photo / Supplied