The Great Debate: Should we sequence our genome?

Sequencing graphs JAN_13When geneticist Craig Venter first suggested that it would soon be possible to sequence complete human genomes for $1000, the scientific community scoffed. This was the year 2000, and the eye-watering costs of the Human Genome Project had just been revealed; nearly $3 billion. For years the ‘$1000 genome’ soundbite was a mocked pejorative; unable to shed its white elephant status.

Dissatisfied, the U.S. Government began to invest heavily in private genomic start-ups. Now, 15 years on, it’s all change. Genetics giant Illumina offer complete genome sequencing for $1000 whilst 23andMe will test for several thousand of the most common genetic mutations for $99. However, whilst it is true that genome sequencing may lead to profound breakthroughs in medicine, its newfound accessibility brings into question the ethics of privacy and discrimination.

The Argument ‘For’ (Tom Gordon)

Today it costs more to have an X-ray on a broken ankle than to receive a complete genetic workup. It is bizarre to think that the most archaic, localised and routine medical practices are now more expensive than a complex and personalised procedure that, only ten years ago, cost nearly a hundred million dollars.

Personalized_Medicine_WheelEvery current healthcare model relies on ‘reactive medicine’, where a person becomes sick and then receives treatment. Symptoms are the markers for disease and the sicker a person, the more obvious their condition. What if the suffering of the patient could be bypassed entirely? ‘Predictive medicine’, where patients are routinely screened before they become symptomatic could become a reality with genomic testing. Thousands of conditions like heart disease have been found to have a strong genetic element. Treatment in advance of symptoms can lead to a much higher quality of life for the patient in the long term. As well as treatment, those who were predisposed to aggravated conditions such as obesity might be able to make meaningful and proactive changes to their lives as a counterbalance. Catching these long-term conditions early could not only lead to a more contented society, but also would likely significantly reduce the financial cost to already stretched health care systems.

Genomic sequencing could combine with nextgeneration medical procedures for particularly effective treatment for diseases like cancer. Current cancer detection methods like biopsies and lumbar punctures are uncomfortable and invasive for the patient, and are only able to detect a malignancy once it has reached a certain size. It has been theorised that that powerful nanoprobes could detect cancers at the microscopic level. Personalised drugs, created using the genetic sequence of the patient, could then deliver a highly specific and effective treatment.

Ultimately, it is possible that a worldwide genetic database could be constructed to identify a slew of heritable diseases. The 100,000 Genomes Project was launched in late 2012 to collate data from thousands of NHS patients into a workable index of genetic diseases. It is now known that 80% of the rarest diseases have some genetic element. With a complete directory, gene therapy would, one day, be able to eradicate famously debilitating and ultimately lethal diseases like Huntington’s and cystic fibrosis.

The Argument ‘against’ (Faiza Peeran)

500px-Autosomal_Dominant_Pedigree_Chart2

Genetic pedigree for autosomal dominant inheritance, such as is seen with Huntington’s Disease

It would be naïve to say that sequencing your genome comes without the risk of emotional cost, especially if you have family around you that may be affected by the results. Among other information, whole genome sequencing gives information about risks and predispositions individuals have to certain diseases. Many people may not want to know if they are at risk for a late-onset or behavioural disorder, especially if they could do little to prevent it. We already know that 90% of adults who are at risk of developing Huntington’s Disease choose not to have a predictive test detailing their status. Some may feel resigned to their fate if told, for example, that they are predisposed to a heart condition, which may give them a passive attitude and make them less inclined to take steps to prevent it. Other issues regarding this may also arise; would you be obligated to tell a relative that they are also at risk for a particular disease, even if they have opted not to test their own genome? If you had children who were at risk because you passed on mutated genes unknowingly, would they blame you for not finding out before you had had children? On the other hand, whole genome sequencing in healthy individuals may not offer any clinical information, as the data collected may be not be very meaningful. Another issue to consider is privacy and fear of genetic discrimination. If everyone sequenced their genome, there will be people who are shown to be predisposed to a certain disorder. There is the danger that insurance companies or employers will be able to access this information and potentially deny coverage or employment. It is also clear that as the technology develops, the criminal justice system would be able to make great use of DNA taken from crime scenes, for example.

However, should such personal information, such as your predispositions to certain diseases, be able to be routinely scrutinised in such cases, especially if it turns out you are not implicated in the crime? People may also be wary of the privacy involved in storage. With their genetic information effectively reduced and available as a computer file, many may feel anxious about the possibilities of such personal information being misused or stolen, especially since identity theft is already a very real and growing threat.

The availability of genome sequencing may also create an issue. Would the cost of testing mean that genome sequencing would only be available to those who could afford it? This could create an underclass of people who would be denied the chance to sequence their genome. They would be, for example, unable to have access to early, preventative healthcare to treat certain predispositions to disorders – which someone who can afford testing would be able to acquire. It’s also important to remember that just possessing the ability to do something new does not create immediate justification for using it – especially in a case such as this, which is naturally awash with ethical issues and considerations. There are also the additional costs attached that are created by the impact of genome sequencing, such as genetic counselling or bioinformatics

Tom Gordon and Faiza Peeran are both studying for an MSc in Science Communication

Images: Feature image: Yang Nan (Shutterstock); Genome cost graph, Personalised Medicine diagram, Huntington’s pedigree (all Wikimedia Commons)

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