We're not prepared for the genetic revolution that's coming

May 25, 2018 by Robert Chapman, The Conversation
There’s no single gene for eye colour. Credit: Shutterstock

When humans' genetic information (known as the genome) was mapped 15 years ago, it promised to change the world. Optimists anticipated an era in which all genetic diseases would be eradicated. Pessimists feared widespread genetic discrimination. Neither of these hopes and fears have been realised.

The reason for this is simple: our genome is complex. Being able to locate specific differences in the genome is only a very small part of understanding how these genetic variants actually work to produce the traits we see. Unfortunately, few people understand just how complex genetics really is. And as more and more products and services start to use genetic data, there's a danger that this lack of understanding could lead people to make some very bad decisions.

At school we are taught that there is a dominant gene for brown eyes and a recessive one for blue. In reality, there are almost no human traits that are passed from generation to generation in such a straightforward way. Most traits, eye colour included, develop under the influence of several genes, each with its own small effect.

What's more, each gene contributes to many different traits, a concept called pleiotropy. For example, genetic variants associated with autism have also been linked with schizophrenia. When a gene relates to one trait in a positive way (producing a healthy heart, say) but another in a negative way (perhaps increasing the risk of macular degeneration in the eye), it is known as antagonistic pleiotropy.

As computing power has increased, scientists have been able to link many individual molecular differences in DNA with specific human characteristics, including behavioural traits such as educational attainment and psychopathy. Each of these genetic variants only explains a tiny amount of variation in a population. But when all these variants are summed together (giving what's known as a characteristic's polygenic score) they begin to explain more and more of the differences we see in the people around us. And with a lack of genetic knowledge, that's where things start to be misunderstood.

For example, we could sequence the DNA of a newborn child, calculate their polygenic score for academic achievement and use it to predict, with some degree of accuracy, how well they will do in school. Genetic information may be the strongest and most precise predictor of a child's strengths and weaknesses. Using could allow us to more effectively personalise education and target resources to those children most in need.

But this would only work if parents, teachers and policymakers have enough understanding of genetics to correctly use the information. Genetic effects can be prevented or enhanced by changing a person's environment, including by providing educational opportunity and choice. The misplaced view that genetic influences are fixed could lead to a system in which children are permanently separated into grades based on their DNA and not given the right support for their actual abilities.

Better medical knowledge

In a medical context, people are likely to be given advice and guidance about genetics by a doctor or other professional. But even with such help, people who have better genetic knowledge will benefit more and will be able to make more informed decisions about their own health, family planning, and health of their relatives. People are already confronted with offers to undergo costly genetic testing and gene-based treatments for cancer. Understanding genetics could help them avoid pursuing treatments that aren't actually suitable in their case.

It is now possible to edit the human genome directly using a technique called CRISPR. Even though such genetic modification techniques are regulated, the relative simplicity of CRISPR means that biohackers are already using it to edit their own genomes, for example, to enhance muscle tissue or treat HIV.

Such biohacking services are very likely to be made available to buy (even if illegally). But as we know from our explanation of pleiotropy, changing one gene in a positive way could also have catastrophic unintended consequences. Even a broad understanding of this could save would-be biohackers from making a very costly and even potentially fatal mistake.

When we don't have medical professionals to guide us, we become even more vulnerable to potential genetic misinformation. For example, Marmite recently ran an offering a genetic test to see if you either love or hate Marmite, at a cost of £89.99. While witty and whimsical, this campaign also has several problems.

First, Marmite preference, just like any complex trait, is influenced by complex interactions between and environments and is far from determined at birth. At best, a test like this can only say that you are more likely to like Marmite, and it will have a great deal of error in that prediction.

Second, the ad campaign shows a young man seemingly "coming out" to his father as a Marmite lover. This apparent analogy to sexual orientation could arguably perpetuate the outdated and dangerous notion of "the gay gene", or indeed the idea that there is any single gene for complex traits. Having a good level of genetic knowledge will enable people to better question advertising and media campaigns, and potentially save them from wasting their money.

My own research has shown that even the well-educated amongst us have poor genetic knowledge. People are not empowered to make informed decisions or to engage in fair and productive public discussions and to make their voices heard. Accurate information about genetics needs to be widely available and more routinely taught. In particular, it needs to be incorporated into the training of teachers, lawyers and health care professionals who will very soon be faced with in their day-to-day work.

Explore further: Natural selection still at work in humans

Related Stories

Natural selection still at work in humans

April 18, 2018
Evolution has shaped the human race, with University of Queensland researchers finding signatures of natural selection in the genome that influence traits associated with fertility and heart function.

Genetic variants linked to type 2 diabetes identified in Chinese populations

April 5, 2018
Researchers investigated genomes from diverse Chinese populations to identify new and known genetic variants that contribute to a person's blood sugar level and risk of Type 2 diabetes. Karen Mohlke at the University of North ...

Scientists herald 'tipping point' in ability to predict academic achievement from DNA

July 19, 2016
Scientists from King's College London have used a new genetic scoring technique to predict academic achievement from DNA alone. This is the strongest prediction from DNA of a behavioural measure to date.

The genetic architecture of risk for autism spectrum disorder

May 16, 2017
A new study of inherited genetic risk indicates that common genetic variations throughout the genome act in addition to rare, deleterious mutations in autism-associated genes to create risk for autism.

Recommended for you

Psychiatric disorders share an underlying genetic basis

June 21, 2018
Psychiatric disorders such as schizophrenia and bipolar disorder often run in families. In a new international collaboration, researchers explored the genetic connections between these and other disorders of the brain at ...

Deep data dive helps predict cerebral palsy

June 21, 2018
When University of Delaware molecular biologist Adam Marsh was studying the DNA of worms living in Antarctica's frigid seas to understand how the organisms managed to survive—and thrive—in the extremely harsh polar environment, ...

Genetic variation in progesterone receptor tied to prematurity risk, study finds

June 21, 2018
Humans have unexpectedly high genetic variation in the receptor for a key pregnancy-maintaining hormone, according to research led by scientists at the Stanford University School of Medicine. The finding may help explain ...

Shared genetics may shape treatment options for certain brain disorders

June 20, 2018
Symptoms of schizophrenia and bipolar disorder, including psychosis, depression and manic behavior, have both shared and distinguishing genetic factors, an international consortium led by researchers from Vanderbilt University ...

Scientists unravel DNA code behind rare neurologic disease

June 20, 2018
Scientists conducting one of the largest full DNA analyses of a rare disease have identified a gene mutation associated with a perplexing brain condition that blinds and paralyzes patients.

Simple sugar delays neurodegeneration caused by enzyme deficiency

June 20, 2018
A new therapeutic approach may one day delay neurodegeneration typical of a disease called mucopolysaccharidoses IIIB (MPS IIIB). Neurodegeneration in this condition results from the abnormal accumulation of essential cellular ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.