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Rare, Well Done: Progress and challenges in rare genetic disorders

In the latest episode of the Genetics Society’s ‘Genetics Unzipped’ podcast, Geneticist Dr Kat Arney takes a look at the progress that’s been made in tackling rare genetic disorders (and the challenges that remain) and we hear from a prenatal genetic counsellor about how new tests are helping people carrying genetic variations make decisions about starting a family.

When it comes to rare genetic disorders, the clue is in the name – it’s a term usually used to refer to conditions that affect fewer than one in two thousand people.  In many cases these disorders are caused by changes in single genes, but in other cases it’s a little more complicated. But although each one may be rare in itself, it all adds up. There are somewhere between 6,000 and 8,000 known rare diseases, with a couple of hundred more being described every year as our ability to delve into the genome grows. In fact, a rough estimate suggests that around one in fifteen people worldwide is affected by one of these rare conditions. So, maybe not so rare after all. But what do we do about them?

Someone who is passionate about making more people aware of rare diseases – and what needs to happen to understand and treat them better – is Dr Ron Jortner, or Roni to his friends. He’s the founder and CEO of Cambridge-based Masthead Biosciences and a trustee of the Cambridge Rare Disease Network (a charity focused on making a difference in the lives of those affected by rare genetic conditions).

“One issue with rare diseases is delayed diagnosis. The average time to diagnosis is 4.8 years, but I’ve seen delays of 20, even 26 years, and this is unacceptable. This is improving as awareness is increasing, and because tools are improving, but it’s still unacceptable that diagnosis takes so long. Awareness of these diseases is much better than it used to be, but it’s still not high enough.”

“When it comes to treatment, gene therapy is still very new. It’s really been around only for a few years and still is facing a lot of hurdles, but I think in the end, this is indeed the dream. This is indeed the method to approach these diseases at the heart of the problem.”

At the same time as we’re understanding more about the variations and faults in DNA that cause rare genetic conditions in order to treat them, there’s an increasingly sophisticated range of tests designed to help people who have these variations make decisions about whether and how they want to have children – or what to do about a pregnancy where a genetic abnormality has been detected in the fetus. 

This is a difficult and emotionally challenging journey to navigate, but there are people like Kira Dineen to help guide the way. She’s a New York-based prenatal genetic counsellor working with people going through a pregnancy or trying to conceive. She is also the host of another podcast about genetics, the excellent DNA Today.

“There are so many tests now, and we can learn so much about the genetics of a child. We’re coming from a place where we used to offer invasive procedures, and that is something that we still continue to do, but less people are going through these procedures because of the new technology we have.”

“But with so much information it’s really advantageous to meet with a genetic counsellor, to go over all this and see how it applies to a person specifically. In genetic counselling, we’re able to sit and really talk through and understand and talk about how this affects the individuals in front of us.”

Full transcript, links and references available online at

Genetics Unzipped is the podcast from the UK Genetics Society, presented by award-winning science communicator and biologist Kat Arney and produced by First Create the Media.  Follow Kat on Twitter @Kat_Arney, Genetics Unzipped @geneticsunzip, and the Genetics Society at @GenSocUK

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Genetics Unzipped / Podcast / Rare Diseases