Steve Connor: Genetic testing can predict but not cure

Lab Notes

Huntington’s disease is a relatively rare genetic disorder that you wouldn’t wish upon your worst enemy. If you carry a single copy of the affected gene you are destined to die a horrible death involving uncontrollable movements, psychiatric disturbances and progressive dementia.

The first symptoms typically occur around the age of 40, and it takes between 10 and 15 more years for the gradual neurodegeneration to end life. Ten years after the excitement of mapping the human genome, and the revolution in the understanding of genetic disorders that the achievement has brought, it is easy to forget that some of those directly affected by inherited diseases have seen little in terms of practical benefit.

The gene involved in Huntington’s disease was mapped to chromosome 4 in 1983 by a team led by Jim Gusella at Harvard Medical School in Boston, but it took another 10 years of intensive effort to isolate and clone the gene itself. This allowed scientists to find the type of changes, or mutations, that cause the disorder – the mutated gene has about two or three times the normal number of ‘GAG repeats.

I remember on both occasions – in 1983 and 1993 – there were optimistic predictions that the discoveries would soon lead to a test for the carriers of the Huntington’s mutation and effective treatments – even possibly a cure – for the disease. The sad fact is that although a relatively cheap and accurate diagnostic test for the Huntington’s mutation has existed for some years, this medical advance has for the affected families arguably produced more misery than it has eradicated. For a start, there has been no accompanying revolution in treatment, largely because there are so few affected people (estimated to be about 12,000 in Britain) to make it worth the expense and effort of the drug companies to develop new therapies.

Secondly, although there is a moratorium in Britain on having to inform insurance companies of the result of such genetic tests, Huntington’s disease is the single, shameful exception. If you have had the test, and are a carrier of the mutation, you are obliged to tell any insurance company who asks for the result. This will come as little surprise to anyone with a passing interest in the history of this disease, which has affected several prominent people, such as the American folk singer Woody Guthrie, who died of the disease in 1967. Huntington’s disease is mired in stigma and prejudice. Early studies of it in the 20th century linked it with witchcraft, and it became a model for the sort of genetic disease that the eugenics movement wanted to target with programmes of compulsory sterilisation. Even today, many affected families prefer to keep their affliction secret because of the perceived stigma attached to it – it is believed that many people request for it not to be put on death certificates.

Alice Wexler was in her early twenties when her mother died of Huntington’s disease and she had no idea that her maternal grandfather and three uncles had also died of it – such was her mother’s sense of shame. Wexler, an historian who has written on Huntington’s, is closer to the science of the disease than are many other members of affected families. Her sister, Nancy Wexler, was part of the Gusella team that discovered the gene. Yet even Alice has declined to take the genetic test (although given her age she appears thankfully to have escaped the worst).

Indeed only 20 per cent of people at risk of Huntington’s actually decide to take the gene test. The reason for this low take-up is quite simple: if you carry the mutated gene there is little you can do about it. Why take the test, especially, if it will do nothing but affect your insurance cover? In the euphoria over the revolutionary advances in the brave new world of genetic medicine, we must remember that, for many people, science in the free-market world of drug development has yet to live up to expectations. Huntington’s disease remains a painful reminder that scientific advances do not always offer practical benefits.

***

As exclusively predicted by this column last year, the Royal Society has confirmed that its next president will be Sir Paul Nurse, Nobel laureate and currently president of the Rockefeller University in New York. Sir Paul is one of those rare scientists whose brilliance has not gone to their head. He will make a good PRS - president of the Royal Society.

PROMOTED VIDEO
News
ebooksNow available in paperback
News
In this photo illustration, the Twitter logo and hashtag '#Ring!' is displayed on a mobile device as the company announced its initial public offering and debut on the New York Stock Exchange on November 7, 2013 in London, England. Twitter went public on the NYSE opening at USD 26 per share, valuing the company's worth at an estimated USD 18 billion.
news

Arts and Entertainment
Martin Freeman and Benedict Cumberbatch as John Watson and Sherlock Holmes in Sherlock
tv

Co-creator Mark Gatiss dropped some very intriguing hints ahead of the BBC drama's return next year

News
people

London 'needs affordable housing'

Arts and Entertainment
music Band accidentally drops four-letter description at concert
News
news
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Female Support Workers / Carers - From £8.00 per hour

£8 - £12 per hour: Recruitment Genius: To assist a young family with the care ...

Recruitment Genius: Customer Service Executive

£20000 per annum: Recruitment Genius: A Customer Service Executive is required...

Argyll Scott International: Commercial Finance Manager

£55000 - £70000 per annum: Argyll Scott International: My client, a world lead...

Argyll Scott International: Commercial Finance Manager

Negotiable: Argyll Scott International: My client, a world leading services pr...

Day In a Page

US immigration: President Obama ready to press ahead with long-promised plan to overhaul 'broken system' - but will it get past a Republican-controlled Congress?

Immigration: Obama's final frontier

The President is ready to press ahead with the long-promised plan to overhaul America's 'broken system' - but will it get past a Republican-controlled Congress?
Bill Cosby rape allegations explained: Why are these allegations coming out now? Why didn’t these women come forward earlier? And why has nobody taken legal action?

Bill Cosby rape allegations explained

Why are these allegations coming out now? Why has nobody taken legal action? And what happens next for the man once thought of as 'America's Dad'
Four years of excruciating seizures caused by the 1cm tapeworm found burrowing through a man's brain

You know that headache you’ve got?

Four years of excruciating seizures caused by the 1cm tapeworm found burrowing through a man's brain
Travelling to work by scooter is faster than walking and less sweaty than cycling, so why aren’t we all doing it?

Scoot commute

Travelling to work by scooter is faster than walking and less sweaty than cycling, so why aren’t we all doing it?
Paul Robeson: The story of how an American icon was driven to death to be told in film

The Paul Robeson story

How an American icon was driven to death to be told in film
10 best satellite navigation systems

Never get lost again: 10 best satellite navigation systems

Keep your vehicle going in the right direction with a clever device
Paul Scholes column: England must learn to keep possession and dictate games before they are exposed by the likes of Germany and Brazil

Paul Scholes column

England must learn to keep possession and dictate games before they are exposed by the likes of Germany and Brazil
Michael Dawson: I’ll thank Spurs after we win says defender as he prepares to return with Hull

Michael Dawson: I’ll thank Spurs after we win

Hull defender faces his struggling former club on Sunday ready to show what they are missing. But he says he will always be grateful to Tottenham
Frank Warren column: Dr Wu has big plans for the professionals yet he should stick to the amateur game

Frank Warren column

Dr Wu has big plans for the professionals yet he should stick to the amateur game
Synagogue attack: Fear unites both sides of Jerusalem as minister warns restoring quiet could take 'months'

Terror unites Jerusalem after synagogue attack

Rising violence and increased police patrols have left residents of all faiths looking over their shoulders
Medecins sans Frontieres: The Ebola crisis has them in the headlines, but their work goes far beyond West Africa

'How do you carry on? You have to...'

The Ebola crisis has Medecins sans Frontieres in the headlines, but their work goes far beyond West Africa
Isis extends its deadly reach with suicide bombing in Kurdish capital

Isis extends its deadly reach with suicide bombing in Kurdish capital

Residents in what was Iraq’s safest city fear an increase in jihadist attacks, reports Patrick Cockburn
Underwater photography competition winners 2014 - in pictures

'Mysterious and inviting' shot of diver wins photography competition

Stunning image of cenote in Mexico takes top prize
Sir John Major: Negative West End portrayals of politicians put people off voting

Sir John Major hits out at theatres

Negative West End portrayals of politicians put people off voting
Kicking Barbie's butt: How the growth of 3D printing enabled me to make an army of custom-made figurines

Kicking Barbie's butt

How the growth of 3D printing enabled toy-designer to make an army of custom-made figurines