With no effective treatment for many of the existing mitochondrial diseases, it is no wonder that scientists have always put a lot of effort into prevention of these diseases. And now, all efforts seem to have paid off with the successful creation of babies - now dubbed “three-parent babies” - through spindle transfer, which is an advanced mitochondrial transfer technique.
Mutations in the genes contained in the mitochondria have been known to be behind diseases and health complications affecting the nervous system and the muscular-skeletal make.
For the parents of the world’s first “three-parent baby”, it had been a decade long struggle marked with several miscarriages and the disheartening demise of two babies. The problem is that the mother carries a mutation in her mitochondria that causes Leigh syndrome, something that robbed her of her two kids as the disease is hereditary.
This is definitely not the first attempt at mitochondrial replacement. In the 1990s, embryology specialists developed the pronuclear transfer technique. In this technique, the father's sperm fertilizes both the mother’s and the donor’s eggs at the same time. Before the fertilized eggs can start the process of cell division and reproduction to form an embryo, each of the eggs’ nucleus is removed. The nucleus from the donor egg is then discarded and replaced with the one from the mother's egg. This has become an approved procedure in some countries across the world.
Owing to their staunch Muslim faith, the parents of the first such “three-parent baby” were opposed to the idea of having to discard an embryo as is the case with pronuclear transfer. A team of fertility researcher and embryologists set out to find a workaround that would prove just as successful in creating a healthy baby. And luckily they have succeeded.
The technique involves fertilizing the mother's egg with sperm from the dad. After successful fertilization, the pronucleus is then transferred into the egg of the donor, from which its own nucleus has already been removed. The result is an embryo with the nuclear DNA from the mother and healthy mitochondrial DNA from the donor. Following healthy development, the embryo is then implanted in the mother’s womb.
The successful use of the technique continues to shine a light so bright for couples who are looking to improve their IVF outcome and avoid transmitting mitochondrial diseases to their offspring. However, only few countries have approved the new method so far. Being a controversial matter, it still remains unclear how long it will take to approve the technique in other countries around the world.