13 Sep 2023 Baby Born via Mitochondrial Donation Gives Hope to Families with Genetic Mitochondrial Disorders

 Mitochondrial DNA is passed down from mother to child, and genetically mutated mitochondria can carry an array of incurable disorders such as muscular dystrophy, multiple sclerosis, epilepsy, neurological problems, seizures, vision and hearing loss, muscle weakness, cognitive and developmental delays, and early death. Earlier this year, for the first time in the United Kingdom (UK), a baby was born with DNA from three people in a procedure designed to prevent the passing of debilitating and fatal genetic disorders from parent to child.

The process, known as mitochondrial donation therapy (MDT), has been touted as the greatest advancement in assisted reproduction technology (ART) since the development of IVF and has the potential to give women who have faulty mitochondria (tiny battery-like structures that generate energy in cells) a chance to have a healthy baby without the risk of passing down their own mitochondrial genetic mutations.

According to The Guardian, which first reported the story, doctors at the Newcastle Fertility Centre in the UK pioneered the groundbreaking procedure, and in 2015, the UK became the first country to pass legislation allowing MDT on a case-by-case basis. Once intended parents are approved for the procedure, MDT allows them to use healthy donor mitochondria instead of their own mutated mitochondria.

So far, the UK’s Human Fertilisation and Embryology Authority (HFEA) has approved at least 30 cases for MDT, although it has not provided specific numbers for participants or births, stating that doing so might breach patient confidentiality. Sarah Norcross, the director of Progress Educational Trust, a charity that improves choices for people affected by infertility and genetic conditions, told The Guardian, “It is also very important that we respect the privacy of children with donated mitochondria, and their parents, not least because these parents are likely to have had prior experience of illness and bereavement in their family.”

The UK is not the first country to create babies from MDT, The Guardian also reported, although the UK is the first to do so in a regulated environment. In 2016, the world’s first MDT birth was reported by doctors in the United States who traveled to Mexico to perform the procedure on a Jordanian woman who carried mitochondrial DNA that caused the fatal condition called Leigh Syndrome. The woman and her husband sought help after having four miscarriages, a child who died at the age of 6, and another who died at 8 months old. The procedure was done without regulations raising ethical questions from peers.

What are Mitochondria?

Mitochondria are organelles that are often referred to as the powerhouses of cells that generate the energy our bodies need to live and function. In essence, when mitochondria do not function properly, cells do not get the energy they need to operate normally. Symptoms of mitochondrial disease are most noticeable in parts of the body that use energy the most, such as the heart, nervous system, muscles, and brain, according to Healthline.

How does Mitochondrial Donation Therapy Work?

The process uses genetic material from three people, the sperm of the father, the egg from the mother, and the egg from a donor. According to The Guardian, during the several-step process, the eggs from the mother and donor are fertilized with sperm from the father, and then in the earliest stages of development, the nucleus of the mother’s fertilized egg is swapped with the donor’s nucleus leaving behind the faulty mitochondrial DNA of the mother and using the donor’s egg with the healthy mitochondrial DNA. The result is an egg that has a full set of chromosomes from the intended parents but carries the healthy mitochondria of the donor. Over 99% of the resulting DNA of the fertilized egg comes from the intended parents while less than one percent of DNA is from the egg donor, which is not enough to affect individual characteristics, per the Daily Mail.

Lifelong Heartache for Families with Mitochondrial DNA Mutations

Michelle Williams, a mother of two, told IFLG during an interview that she had no idea that she or her family members carried faulty mitochondrial genes until her daughter Miranda was diagnosed at age 7 with myoclonic epilepsy with ragged-red fibers (MERRF), a rare mitochondrial disorder. She said that looking back before the diagnosis, there were signs, such as when her daughter failed to meet certain milestones, was unable to walk heel-to-toe, and exhibited clenching fists, breathing issues, and a lack of balance that was often chalked up to clumsiness. At the time, Williams and her family had not heard of mitochondrial DNA or genetic mutations pertaining to mitochondria.

After several misdiagnoses, which included an incorrect diagnosis of asthma, a genetics doctor finally tested Miranda for mitochondrial disorders and confirmed she had MERRF. This prompted Williams and her sister, who also battles health issues, to get tested as well, revealing positive results for the mutation in both sisters. Sadly, over the course of the next eight years, Williams slowly watched her daughter lose the ability to walk, breathe on her own without a ventilator, eat on her own, use her fingers, talk, or smile. In the end, her body didn’t have enough energy to keep moving and functioning. Miranda passed away at the age of 15 from respiratory and heart failure, mouthing to her mother in her final days, “Mommy, I want a hug.”

Williams goes on to say that had she known she was a carrier of mitochondrial DNA mutations, she may not have had any children and is glad she did not have another child after Miranda.

What Mitochondrial Donation Therapy May Mean for Future Families

William’s story is just one of many that shed light on how unhealthy mitochondria can affect entire families with illness, loss, and life-long bereavement and how MDT may provide hope for intended parents who are carriers of mitochondrial disorders. Peter Thompson, chief executive at HFEA, tells The Guardian, “MDT offers families with severe inherited mitochondrial illness the possibility of a healthy child.”

Williams went on to say when speaking about her family, “My nieces also carry the gene, and I am 100 percent thrilled that the UK has created this amazing technology. I hope that someday it will be available in the US so that my nieces are able to use it. They are so scared to have any children in the future, as we all watched our Miranda girl slowly deteriorate. This opens up the possibility that they can have healthy children without the fear of them having a short or suffering life.”

Although long-term follow-up, ongoing research, and an established regulatory system are essential, we are optimistic that this new evolution in assisted reproductive technology will help many intended parents have biological children who would otherwise not have considered it in the past for fear of passing on severe mitochondrial disorders. Advancements in ART continue to break down barriers for thousands of people who thought parenthood would never be possible. ART produces hope, and for our team of experienced legal professionals at International Fertility Law Group, hope is what we are here for.