A $15 million federal grant is soliciting applications from clinics to conduct a pilot and clinical trial of mitochondrial donation techniques before it can be offered to affected families.
Mitochondrial donation combines the DNA of the eggs of two different women and the genetic material of more than two people: the mother, father and egg donor. The gene combinations created would be inherited by subsequent generations.
One mitochondrial donation technique involves removing the nucleus of a mother egg from the surrounding gelatinous cytoplasm containing unhealthy mitochondria and inserting the nucleus into a donor egg containing healthy mitochondria from which the nucleus has been removed.
“When you think of a chicken egg, the protein is there to help the chicken grow, similar to the cytoplasm of a human egg, and the yellow yolk is like the nucleus that contains the genetic DNA of all those traits that parents pass on on their offspring, such as eye and hair color,” said Mills.
The UK was the first country to legally offer mitochondrial donation to patients in 2017.
Bethany Hodge discovered she was a carrier of mitochondrial disease when her younger sister Annaliese was diagnosed at age 18 after years of unexplained muscle tremors, poor balance and speech problems.
“I’ve always dreamed of having a baby who had a part of me in them,” said Hodge, 29. “But that’s not something I want my child — and their future children — to face. .”
What is Mitochondrial Disease?
Mitochondrial disease is a group of 300 different disorders caused by mutations in the mitochondria – structures in the gelatinous fluid that surrounds the nucleus of each cell.
These mitochondria are essential for converting the energy from the sugars, fats and proteins in food into the energy that powers the body’s cells.
It is estimated that between one in 5,000 and one in 10,000 Australians will develop severe or life-threatening mitochondrial DNA disease during their lifetime.
About 50 babies are born each year with a life-threatening form of mitochondrial disease, and many die before the age of five.
The hereditary condition can seriously affect entire families, resulting in organ failure, blindness, deafness, brain disorders and muscle problems. There are no effective treatments.
Hodge and her partner James Frost see mitochondrial donation as their best chance of conceiving a child that carries both their genetic makeup. Boosting egg donations would bring them one step closer to this goal, she said. “It would help so many families break this vicious circle.”
One of the challenges to mitochondrial donation research is an acute shortage of donated eggs, Mills said.
Demand for donor eggs — both for prospective parents and researchers — significantly outstrips supply, national data shows.
Meanwhile, the number of women freezing their eggs has risen dramatically.
In 2019, women underwent 3,395 egg freezing cycles, nearly triple the number of cycles just four years earlier, according to the Australian and New Zealand Assisted Reproductive Database.
In Victoria alone, nearly 5,000 women had eggs in storage as of June 30, 2021, 23 percent more than a year earlier, data from the Victorian Assisted Reproductive Treatment Authority shows.
It’s too early to know how many of these women will return to use their eggs, although a small study from the UK estimates that less than 20 percent do.
Mills likens her proposal to opt out of organ donation programs abroad, where being an organ donor is the default from birth unless individuals opt out. “Women who want to freeze their eggs will be informed of their options from the start and always have the choice to opt out at any time.”
She said the change requires a broadening of national guidelines regarding egg donation for research purposes, a change in consent and counseling, and possibly the creation of a national gamete bank, where sperm and eggs would be available for a range of ethically approved research projects.
Chief executive of the support and awareness organization Mito Foundation Sean Murray said access to donated eggs would be crucial for the pilot program to continue.
“It’s important that women are involved in these discussions, which will no doubt raise questions, and it would be great if they were made aware of the potential benefits of donating eggs to research,” he said.
“My hope for my family and for all people affected by mitochondrial donation is that they have the choice to use mitochondrial donation to prevent passing mitochondrial diseases to the next generation,” Murray said.