Mary Dejevsky: Genetic testing has little value if there's no chance of a cure

If you submit to screening at, say, the age of 40, and learn that you have a predisposition to Alzheimer's, what are you supposed to do about it?

Share
Related Topics

Sometimes it is hard not to feel that the media and the medics between them have things the wrong way round. Earlier this week, a report from the Human Genetics Commission recommended that genetic testing for a range of conditions be made available to couples contemplating having children. The findings have more committees to pass through before they are acted upon, but the Commission said that there were "no specific social, ethical or legal principles" against pre-conception screening. At this point, the whole subject sank like a stone.

Go back a week, though, and another report made far bigger, far noisier waves. Scientists from the universities of Cardiff and Pennsylvania announced the identification of five gene variants that raise the risk of Alzheimer's disease. Much was made of the numbers likely to suffer from Alzheimer's (an estimated 1 million by 2021) and the cost of care (currently £23bn a year). It is not the scientists' fault, but the tenor of the reporting suggested that prevention or cure might be just around the corner.

There are some obvious reasons why these two items of news from the medical genetics front were received so differently. One is that Alzheimer's, second only to a cancer diagnosis, is the fate very many people fear, for ageing relatives and for themselves. Another is that the Alzheimer's research appeared to offer unadulterated good news: quantifiable progress towards a much-desired end – five whole new gene variants found at once. The news about pre-conception screening, on the other hand, held out no hope of cures and could be interpreted as potentially blighting a couple's hopes.

Of these two developments, however, I would argue that the possibility for couples to be screened for conditions they might pass on is by far the more significant and beneficial here and now. Discovering genetic markers for Alzheimer's is still – if you read the small print of last week's reports – at a very early stage; thus far, there is no single one that determines whether someone will develop Alzheimer's, and there may never be. It may always be a combination of different genetic variants and environmental factors.

The crucial distinction in my mind, however, is that pre-conception screening allows individuals to make an informed choice. They are tested for the propensity to pass on a condition that has already been identified – which, of course, is by no means all. They can then consider what to do about it. That might entail a decision not to have children. It might mean exploring the options for test-tube screening of embryos. It might prompt a subsequent decision to end a pregnancy, or even a relationship – but surely better at that point than for one or other parent to conclude later that they cannot or do not want to cope. At very least it would mean that if the couple decide to have children, they are forewarned and so forearmed.

With Alzheimer's, it is not just that knowledge about the genetic components is still at a very preliminary stage, but that the possibilities even for slowing, let alone preventing the onset of the condition, are extremely limited. If you submit to screening at, say, the age of 40, and learn that you have a predisposition, to some unknown degree, to Alzheimer's, what are you supposed to do about it? It is difficult not to believe that the awareness alone would not in some way overshadow your whole life, as you kept watch for seemingly tell-tale symptoms. If and when an effective treatment is developed, through drugs or gene therapy, the calculation will change. But even at the speed with which the science of genetics is advancing, prevention or cure looks many years away.

At least a system of universal access to healthcare, such as most European countries maintain in one form or other, obviates the other great risk that arises from genetic testing. It was President Clinton who decreed that commercial health insurance companies in the United States should not be able to weight policies according to the results of genetic testing. As genetics advances, however, the line will be ever harder to hold, as insurers press for the knowledge that holds the key to certain profits. This is why the US health insurance model, even as liberalised by Barack Obama, is likely one day to become unsustainable, as it seeks to lock out those predisposed to develop one expensive debilitating condition or another.

Regardless of the uniquely ruthless US health insurance system, however, it is worth asking whether there is not something unethical about offering people genetic tests for conditions that are not – or not yet – treatable. This is not a problem with pre-conception testing, as the question posed is quite different, and, whatever the results, there is a remedy. But what about genetic testing for Alzheimer's?

As someone whose husband has what may well be an inherited form of Parkinson's disease, where genetic research seems to be at a similar stage to that of Alzheimer's, I am not sure what practical purpose testing would serve. When we married, the burden of scientific opinion was that Parkinson's was not inherited. His own family history suggested otherwise. Now, much of the research being conducted around the world is geared towards identifying genetic mutations, with one – known as LRRK2 – strongly associated with a strain of Parkinson's that manifests itself long before old age. It is possible to test for this.

At the World Parkinson's Congress, held in Glasgow last year, an American radio journalist recently diagnosed with the condition, who had a father and a brother who were also sufferers, described his dilemma on being offered such a test. After consulting close family, he declined. He never actually said why, and maybe his grown-up children feared pressure to be tested, too, and the possible effects of such knowledge on their quality of life and insurability. But it is possible to imagine, too, that, with no treatment available, he felt the scales of advantage weighted against him. Altruism might militate in favour of taking a test, for the sake of medical research; his own long-considered preference was not to know. And who can blame him? Perhaps it is part of the human condition not to bow to determinism until you have to.

m.dejevsky@independent.co.uk

React Now

Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Recruitment Genius: Business Analyst - 12 Month FTC - Entry Level

£23000 - £27000 per annum: Recruitment Genius: A Business Analyst is required ...

Recruitment Genius: Chefs - All Levels

£16000 - £23000 per annum: Recruitment Genius: To succeed, you will need to ha...

Recruitment Genius: Maintenance Engineer

£8 per hour: Recruitment Genius: This is an opportunity to join an award winni...

Recruitment Genius: Telesales Executive & Customer Service - Call Centre Jobs!

£7 - £9 per hour: Recruitment Genius: Are you outgoing? Do you want to work in...

Day In a Page

Read Next
George Osborne appearing on the BBC's Andrew Marr Show on Sunday, 5 July 2015  

George Osborne says benefits should be capped at £20,000 to meet average earnings – but working families take home £31,500

Ellie Mae O'Hagan
The BBC has agreed to fund the £650m annual cost of providing free television licences for the over-75s  

Osborne’s assault on the BBC is doing Murdoch’s dirty work

James Cusick James Cusick
Greece debt crisis: EU 'family' needs to forgive rather than punish an impoverished state

EU 'family' needs to forgive rather than punish an impoverished state

An outbreak of malaria in Greece four years ago helps us understand the crisis, says Robert Fisk
Gaza, a year on from Operation Protective Edge: The traumatised kibbutz on Israel's front line, still recovering from last summer's war with Hamas

Gaza, a year on from Operation Protective Edge

The traumatised kibbutz on Israel's front line, still recovering from last summer's war with Hamas
How to survive electrical storms: What are the chances of being hit by lightning?

Heavy weather

What are the chances of being hit by lightning?
World Bodypainting Festival 2015: Bizarre and brilliant photos celebrate 'the body as art'

World Bodypainting Festival 2015

Bizarre and brilliant photos celebrate 'the body as art'
alt-j: A private jet, a Mercury Prize and Latitude headliners

Don't call us nerds

Craig Mclean meets alt-j - the math-folk act who are flying high
How to find gold: The Californian badlands, digging out crevasses and sifting sludge

How to find gold

Steve Boggan finds himself in the Californian badlands, digging out crevasses and sifting sludge
Singing accents: From Herman's Hermits and David Bowie to Alesha Dixon

Not born in the USA

Lay off Alesha Dixon: songs sound better in US accents, even our national anthem
10 best balsamic vinegars

10 best balsamic vinegars

Drizzle it over salad, enjoy it with ciabatta, marinate vegetables, or use it to add depth to a sauce - this versatile staple is a cook's best friend
Wimbledon 2015: Brief glimpses of the old Venus but Williams sisters' epic wars belong to history

Brief glimpses of the old Venus but Williams sisters' epic wars belong to history

Serena dispatched her elder sister 6-4, 6-3 in eight minutes more than an hour
Greece says 'No': A night of huge celebrations in Athens as voters decisively back Tsipras and his anti-austerity stance in historic referendum

Greece referendum

Greeks say 'No' to austerity and plunge Europe into crisis
Ten years after the 7/7 terror attacks, is Britain an altered state?

7/7 bombings anniversary

Ten years after the terror attacks, is Britain an altered state?
Beautiful evening dresses are some of the loveliest Donatella has created

Versace haute couture review

Beautiful evening dresses are some of the loveliest Donatella has ever created
No hope and no jobs, so Gaza's young risk their lives, climb the fence and run for it

No hope and no jobs in Gaza

So the young risk their lives and run for it
Fashion apps: Retailers roll together shopping and social networking for mobile customers

Fashion apps

Retailers roll together shopping and social networking for mobile customers
The Greek referendum exposes a gaping hole at the heart of the European Union – its distinct lack of any genuine popular legitimacy

Gaping hole at the heart of the European Union

Treatment of Greece has shown up a lack of genuine legitimacy