TV Review: EastEnders – Stem cells in Albert Square

When a storyline on a television soap involves acute myeloid leukaemia (AML), stem cell transplantation, donor matching and the genetics of biological relationships, it is difficult for me, as the genetics editor at BioNews, not to take notice.

For me, it is particularly interesting because I have watched EastEnders from its very first episode in 1985. I have seen characters come and go, families arrive and disappear, marriages, murders, affairs, births and deaths unfold on Albert Square. So when Denise Fox was diagnosed with AML, the unfolding storyline brought together several subjects that are highly relevant to us.

At its centre is Denise's need for a stem cell transplant after her chemotherapy fails to work as hoped. Her family members are tested but none is a suitable match, leaving her dependent on the search for an unrelated donor. But alongside the transplant storyline is an unexpected genetics twist: the discovery of Denise's previously unknown paternal half-brother, Darnell Larson Jr, through an ancestry website.

Suddenly, the storyline isn't just about finding a stem cell donor. It is also about genetics – how we establish biological relationships, what we inherit from our parents and how those inherited characteristics can influence whether one person can become a suitable donor for another.

I have watched EastEnders for more than 41 years, but I don't think I have ever done it quite like this. I am now watching not only as someone who has grown up with the characters, but as a scientist and science writer who spends much of her working life thinking and writing about genetics and biomedical research.

It is a storyline that could easily have been reduced to a familiar soap formula: desperately ill character needs a transplant; mysterious long-lost relative appears; relative turns out to be the perfect match; cue emotional music and a happy ending.

Instead, so far, EastEnders has actually taken the opportunity to explain some of the science behind stem cell donation.

One of the things I particularly liked was the explanation that finding a stem cell donor isn't simply a matter of finding someone with the same blood group. The important factor is tissue type, including human leukocyte antigen (HLA) markers, which are inherited from our parents. A family member may therefore be more likely to be a suitable donor, but being related does not automatically mean that someone will be a match.

That distinction matters. It also matters particularly for people from minority ethnic backgrounds. This is explained in one scene:

Jack Branning, Denise's partner, says: 'Denise needs stem cells. She needs a stem cell donor. Kim and the kids aren't a good enough match.'

Darnell replies: 'But I might be.'

Kim Fox, Denise's sister, remarks: 'People of colour, we have half the chance that white people do at finding matches on the donor register.'

I actually stopped to think about this. How many EastEnders viewers will have heard that of that issue before? Probably not many. It moved the subject beyond Denise's individual predicament and highlighted a real problem facing patients who need a stem cell transplant.

The reason is partly genetic. HLA types are inherited, and the diversity of HLA types within populations means that a patient is more likely to find a suitable donor among people with a similar ancestry. But the donor registers do not reflect the diversity of the patients who need them. For someone from a minority ethnic background, finding a matching unrelated donor can therefore be much more difficult.

That is why the donor drive in EastEnders is more than a convenient plot device. It is also why the arrival of Denise's previously unknown half-brother is so intriguing scientifically. The family discover him through an ancestry website and he becomes a potential donor. The dramatic reveal is classic EastEnders, but the underlying genetics is considerably less predictable.

A half-sibling shares, on average, around 25 percent of their genetic variants with you, compared with around 50 percent for a full sibling. That does not mean a half-sibling has a 25 percent chance of being a stem cell match. HLA inheritance is more complicated than that, and the relevant markers have to be tested directly. Darnell could be a suitable donor, but his relationship to Denise alone cannot tell us whether he will be.

I am used to seeing genetics and biomedical research discussed in scientific papers, press releases and specialist articles. I spend my working life writing about genetic conditions and research. But millions of people who would never choose to read about HLA matching or stem cell donation in a scientific article are being introduced to these subjects while sitting down to watch their favourite soap.

Medical storylines can be particularly effective because viewers become emotionally invested in the characters before they become interested in the science. When we care about whether Denise survives, we also start to care about whether a donor can be found.

There is, inevitably, plenty of drama. Discovering a previously unknown half-brother through an ancestry website just as Denise needs a stem cell transplant is a very EastEnders twist. It would be a remarkable coincidence anywhere other than in Albert Square.

For now, the most important message is not whether a soap character gets her happy ending. It is that there are real people waiting for theirs – and for some of them, finding the right donor is much harder than it looks.

If you're interested in becoming a stem cell donor, you can join the blood cancer charity DKMS UK's register, the Anthony Nolan's stem cell register, or the NHS' stem cell donor registry. You could potentially give someone the chance of the happy ending that Denise is still waiting for.