Prof. Andrew Shelling sorts fact from fiction when it comes to 'blaming your genes,' and discusses the role of genetic testing in controlling common diseases. From Raising the Bar Home Edition.

The ability of genetics to predict both human disease and behaviour is an exciting and constantly evolving field, however, it's important to sort fact from fiction when it comes to 'blaming your genes'.

In this talk, medical researcher Andrew Shelling covers the red herrings of genetic research and explains where advances are really being made.

From Raising the Bar - Home edition 2022

Listen to Professor Andrew Shelling's talk

https://youtu.be/Aa54SVR5zxU

Edited highlights from the discussion

The world of lifestyle genetics is a very murky one.

There are a whole lot of things that are not diseases but traits, like baldness, food preference, freckles, or addiction, which now have genes associated with them.

Companies have been going direct to consumers asking them to spit into a tube and get information about these genes. Often these types of genetic tests target the worried well, especially through social media.

One of the controversial ones that's popped up over the last few years is the gay gene. People have gone looking for it. A recent study that came out just a few years ago, published in a really good journal, studying large numbers of people found only five hits. So there's no gay gene. Instead, there are some weak associations. One of them was related to the sense of smell. And one of the other associations was with male pattern baldness, which again speaks to some sort of hormone interaction.

Some lifestyle genetics have been exploited by different companies that are going direct to consumers. I refer to these as genetic horoscopes: they may be interesting, they may be real, but they are not always based on robust science.

So, we'll move now to the claim that genetics could predict the age that you lose your virginity. At face value, this seems sensational. But if you really were to think about it, the age at puberty is very well-defined event in people's lives.

If you go back 200 years people went through puberty aged 18 or 19, now aged 12 or 13. There are clearly some factors that are at play there, probably related to good health and body weight that'll allow puberty to happen earlier. By contrast, the age at which menopause begins is fixed; it hasn't changed for thousands of years.

So what this study was really doing in asking nearly 400,000 people about what age they lost their virginity, -which is probably a marker for puberty - was establishing a few hundred gene variants that seemed to be clearly associated…

Go to this episode on rnz.co.nz for more details