Video Review: Mitochondria Replacement - Some Facts

Mitochondrial replacement has been making the headlines this year, but understanding the science behind it is no small task. Cue a whiteboard, some marker pens and two informative narrators and you have the recent educational animation from the Human Fertilisation and Embryology Authority (HFEA) on precisely this topic.

This whiteboard animation has been used to great effect to communicate the science behind two new IVF-based techniques to prevent mitochondrial diseases, as part of the HFEA's public consultation on the ethics of these emerging techniques.

The short video is engaging with its clever use of speeded up, animated drawings showing the artist's hands at work. The drawings are accompanied by voice-overs providing simple descriptions of the pictures as they evolve, starting with basic cellular structure, the nucleus and then mitochondria. When explaining how nuclear DNA is made up by a mix of chromosomes from our parents, the image used is reminiscent of Leonardo da Vinci's Vitruvian man set simultaneously in a circle and square.

Da Vinci's man and nature imagery is then cleverly contrasted with the metaphor of man and machine as the artist sketches the mitochondrial DNA as a power station, symbolising its role in producing the energy our cells need. The fact that the power station also visually provides electricity to the metaphorical light bulb may be a little too much symbolism, but it enables the artist to use the image of a darkened, switched off light bulb when describing the effects of mitochondrial diseases.

The illustrations are interspersed with the artist writing on the screen. This helps convey a large number of facts without the audience losing concentration. With a few strokes of the pen, the video explains that mitochondrial disease is passed down exclusively from the mother's side, that it is caused by mutations of the mitochondrial DNA, that the symptoms affect a variety of organs and that there is no cure at present.

The artist goes on to write out a numbered list of the options for intending mothers, namely having no children, adoption, egg donation and prenatal diagnosis (PND) or preimplantation genetic diagnosis (PGD). Simply seeing the list written before your eyes makes it easier to remember than with a run-of-the-mill PowerPoint presentation.

The remainder of the video delves into the science behind the two new techniques that may help women with more complicated mitochondrial diseases, who wish to have a genetically related child but where PND or PGD may not lead to a child free from mitochondrial disease.

Clear and easy-to-follow explanations first guide the viewer through maternal spindle transfer, where prior to fertilisation the spindle of chromosomes from the donor egg is removed and replaced with the spindle from the egg of the intending mother. Pro-nuclear transfer is then tackled, with clear-cut sketches depicting how after eggs from the donor and intending mother are fertilised, the pro-nuclei are removed from the egg donor's embryo and replaced with the pro-nuclei from the intending mother's embryo.

The video ends by posing the question 'What do you think about this form of treatment and about the social and ethical issues it may raise?'. The only possible criticism of the video I have is that although it provides sufficient grounding in the science to follow debates on the ethical issues, it leaves the audience without any pointers to what the ethical issues are. It requires considerable perseverance navigating the HFEA's website to find the signposting to further videos that deal with these issues. Finding these videos is a more difficult task than understanding the science!