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Myths and facts

Fake news and misinformation within medicine and healthcare is a serious problem. The advent and popularisation of social media has enabled the flow of misinformation on a global scale. The COVID-19 pandemic is a key example of how misinformation can be dangerous. Despite evidence highlighting hydroxychloroquine’s lack of safety and efficacy, the President of the United States, Donald Trump has continued to advocate its use.

The genomics field is no exception to the spread of misinformation: “all mutations are bad”, “it’s in my genes so I can’t help it,” “I’ve got a perfect genome”… In this blog, we will explore some of the common myths and misconceptions surrounding genomics and what can be done in order to spread the truth.

“All mutations are negative”

Studies have shown that the majority of the public associate the word ‘mutation’ with something bad or abnormal. These perceptions are largely drawn from popular culture, particularly science-fiction, where mutations result in a dramatic physical change to an individual. For example, in the X-Men film series so-called mutants, despite being superheroes, are in fact shunned by governments and feared by many humans.  Nonetheless, popular culture can build bridges for individuals to build on, making genetics a more social concept.

Mutations are naturally occurring changes in the DNA sequence, which account for some of the 0.1% difference between two individuals. Estimates suggest that the average person is born with 60 new genetic mutations. In most cases, mutations have no effect and in some cases, they can actually be beneficial. For example, the CCR5-del32 mutation has been found to confer resistance to HIV.

Within genetic counselling, there has been a shift in using the term mutation in clinical practice. In the ACMG/AMG guidelines, it encourages individuals to replace the terms ‘mutation’ and ‘polymorphism’ with ‘variant’. These guidelines have not only aimed to move away from language that may be regarded as offensive, it has also been a step in the right direction towards standardisation and consistency.

“One gene, one trait”

This myth is largely down to the teaching of genetics at school. We all remember, punnet squares and using lowercase/uppercase letters. Well in fact, genetic traits are much more complicated than that. Monogenic disorders, such as cystic fibrosis, are caused by variations in a single gene. Even these disorders are affected by other factors, including penetrance, background variation and environmental factors, which influence the severity of the disease. Most traits and disorders are multifactorial, influenced by many genes and different environmental factors. For example, so far, as many as 15 genes have been associated with eye colour. Additionally, eye colour can naturally change in response to the iris expanding or contracting in the presence of light. These traits, such as height, eye colour and skin colour, do not represent distinct classes but instead follow a continuum.

“It’s in my gene…”

People often believe that the genes you inherit explain exactly who you are. This is partly because Mendel’s original examples were focused on genes whose effects could be readily identified. This has led to the assumption that there is a gene for arbitrary traits, for example, a reported ‘gay gene’. Media presentation of a gene for specific traits largely oversimplifies the majority of situations.

On the other hand, people believe that your genes control everything about you and that you can’t do anything about it. A prominent example can be seen within obesity. There are 97 known gene variants that are thought to influence people’s chances of being overweight or obese. The strongest association has been found in the FTO variant. People with two copies of the variant weigh on average 3kg more and are 1.7 times more likely to be obese. While this variant makes people more likely to be overweight, it does not affect their ability to lose weight through diet and exercise or other treatments. In fact, researchers found no differences between weight loss outcomes in individuals with and without the variant.

“Cancer is inherited”

People often fear that because someone in their family has had cancer, they are also likely to get it. This is not necessarily the case. Only about 5-10% of cancers are caused by hereditary variants. Cancers that are the result of inherited variants and affect multiple family members are known as ‘familial’ cancers. In these cases, individuals with a strong family history can seek genetic testing and support from genetic counsellors. The remaining 90-95% of cancers are caused by mutations that happen throughout an individual’s lifetime as a result of ageing and environmental exposures, such as smoking and radiation. These cancers are known as ‘spontaneous’ cancers.

“A perfect genome”

Some individuals believe that when nothing runs in their family, they have the perfect genome. Some disorders carry stigma and families can deny that the trait came from their side of the family. This is particularly the case for recessive conditions where you often don’t see any history in the family. This is because two carriers can have offspring with disease, without directly having it themselves. Everyone has natural variation, which makes every individual unique (even twins). It is important that people recognise and understand that we all have some alterations within our genes, which we could subsequently pass on to potential offspring.

Another issue is the misconception regarding genes and variants. A prominent example is the BRCA1 gene. It is commonly miscommunicated, particularly in the media, regarding the ‘breast cancer gene’. Everyone has a BRCA1 gene and is very important in the DNA damage response. Individuals at risk of breast and ovarian, carry a variant in the BRCA1 gene which means that it does not function properly. As a result, damage in their DNA can accumulate and lead to cancer.


New media, particularly internet search engines and social media, are now becoming well-accepted sources for customised health-related information. Several studies have highlighted that people are most likely to turn to the internet for science and health-related information. However, the quality and accuracy of information from these channels is an ongoing concern. While not everyone wants to be actively engaged in genomics, it is important that accurate and open information is available to people if they need it. Professional medical organisations should do more to educate patients and the public about what sources are most appropriate. These sources need to be continually monitored to provide the public with up-to-date reliable information. Furthermore, educating about genomics, particularly within schools, needs to be delivered in an engaging manner with the implications of genomics for society being highlighted.

Image credit: By TheaDesign –

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Ethics / Genomics / Mutations