Behind his infectious smile and cheeky spirit, baby Cooper was suffering.
Shortly after he was born, Elizabeth Tierney's son was diagnosed with a rare and life-threatening form of mitochondrial disease, also known as mito.
The debilitating genetic disorder starves the body's cells of energy, causing multiple organ dysfunction or failure and potentially death,
"It was devastating," Ms Tierney told SBS News of Cooper's time in and out of hospital.
"We had oxygen tanks, he was receiving 26 doses of medication each day ... you don't plan a family with the thought that that even existed."
A fighter to the end, Cooper lost his battle with the disease after just six months. Now, his mother hopes to see a new technique introduced to help prevent the disease.
Elizabeth Tierney's son Cooper was diagnosed with a severe form of mitochondrial disease. Source: Supplied
What is mitochondrial disease?
Mitochondria are found in the fluid surrounding the nucleus of cells and are responsible for making about 90 per cent of the energy the body needs to function, the AMDF says. In order to work, mitochondria have their own mitochondrial DNA (called mtDNA).
Mitochondrial disease can occur when mitochondria stop working and fail to produce energy.
It can appear mild, with little or no symptoms, or it can be severe and potentially life-threatening.
The disease can potentially cause strokes, hearing and sight loss, and the inability to walk, eat, swallow or talk. It can also lead to liver disease, diabetes, heart, respiratory and digestive problems and intellectual disabilities.
One Australian baby is born every week with a severely disabling form of the disease, according to the ADMF.
Sadly, most children diagnosed with the disease die in the first five years of life.
The disease can be caused by genetic mutations in the nuclear DNA, inherited from a mother and a father, or in the mtDNA which is passed on from the mother.
In the Tierney's case, both Elizabeth and her husband Robert passed on a very rare genetic mutation in a nuclear gene to their son, which triggered the disease.
In the other half of all known cases where the disease is caused by mtDNA mutations, the only option for most couples to prevent it from being passed onto their children is an IVF procedure called "mitochondrial donation".
What is mitochondrial donation, and is it legal?
Mitochondrial donation involves replacing mitochondrial DNA from the mother with healthy mitochondrial DNA from the egg of a woman who is a donor.
It only assists women with mtDNA mutations and helps in reducing the risk of mothers with this form of mitochondrial disease passing it on to their children.
The technique is legal in the UK but is not currently allowed in Australia. In late March, Federal Health Minister Greg Hunt introduced to parliament
The treatment involves replacing mitochondrial DNA from the mother with healthy mitochondrial DNA from the egg of a woman who is a donor. Source: SBS News
"Here in Australia each year around 56 children are born with a severe form of the disease - this equates to approximately one child per week," Mr Hunt told parliament on 24 March.
"The tragic prognosis for these children and their families is that many will pass within the first five years."
The government's bill - known as Maeve's law - is named after five-year-old Maeve Hood, the daughter of Joel and Sarah who live in Mr Hunt's Victorian electorate.
It only assists women with mtDNA mutations and helps in reducing the risk of mothers with this form of mitochondrial disease passing it on to their children. Source: SBS News
Maeve has a severe type of mitochondrial disease which was diagnosed at 18 months.
"She is bright, she is bubbly, a beautiful young girl, but she suffers from the most challenging of medical issues," he said.
"Maeve is thankfully still with us but her family still lives with daily uncertainty about the future."
AMDF chief executive Sean Murray said allowing the technique could put an end to the suffering endured by Australian families.
Federal Health Minister Greg Hunt. Source: AAP
"What that can mean for some families ... [who have] experienced multiple generations of mitochondrial disease impacting their family, is that this can put an end to the suffering," he told SBS News.
A controversial technique
The technique is also controversial, given it combines DNA from three people - the mother, father as well as mitochondrial DNA from the donor egg.
It has been labelled immoral, unethical and open to misuse. And, while it has been the subject of several scientific reviews, there is no guarantee of its safety and effectiveness.
Reverend Kevin McGovern, a Catholic ethicist, opposes the legalisation. He argues the technique is less effective and less safe than couples conceiving through a donor egg, where the baby would not be biologically related to the mother.
The fact that DNA comes from three people - the vast majority from the parents and a tiny percentage from the donor - makes the technique controversial. Source: SBS News
"I continue to believe that we offer that child the best chance of a happy and healthy life by using the current treatment, which would be to fertilise the donated egg with the husband's sperm," he told SBS News.
"I recognise that making the decision to proceed with the existing care means that the woman must let go of other dream of having a child which is genetically related to her. And I don't in any way underestimate the seriousness of that."
Dr David Thorburn is from the Murdoch Children's Research Institute. He has diagnosed and researched the disease for three decades, and says Australia has the expertise in mitochondria, IVF and ethics to offer the procedure.
"In Australia, the scientific consensus has been that this disease is completely distinct from all other forms of inherited disease," he told SBS News.
"And so, it is actually relatively easy to put a boundary around what is mitochondrial donation. You can restrict it to only replacing the mitochondrial genome, and it has no real implications for other techniques like germline gene editing."
A 'staged and closely monitored' process
The procedure has been the subject of a and public consultations from the National Health and Medical Research Council.
The government is proposing to introduce mitochondrial donation in a "staged and closely monitored way".
"The aim is to allow families to access the technique safely, at a carefully selected and regulated clinic. Ongoing research will also be allowed to increase Australian-based knowledge and expertise,"
"Once the clinic has demonstrated success over a number of years, and the results have been evaluated by experts, there will be an option to allow for licensed clinics across Australia to offer mitochondrial donation."
Labor, Liberal and Nationals MPs will have a free vote on the bill given that some members and senators have previously opposed laws that allow genetic modifications.
With reporting by AAP.
