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.

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksA celebration of British elections
  • Get to the point
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

Ashdown Group: Project Manager - Birmingham - up to £40,000 - 12 month FTC

£35000 - £40000 per annum: Ashdown Group: IT Project Manager - Birmingham - ...

SThree: Recruitment Consultant - IT

£25000 - £30000 per annum + Uncapped Commission: SThree: Sthree are looking fo...

SThree: Trainee Recruitment Consultant - Dublin (based in London)

£20000 - £25000 per annum + commission: SThree: Real Staffing's Pharmaceutical...

SThree: Trainee Recruitment Consultant

£18000 - £25000 per annum + Commission: SThree: Are you great at building rela...

Day In a Page

Fishing for votes with Nigel Farage: The Ukip leader shows how he can work an audience as he casts his line to the disaffected of Grimsby

Fishing is on Nigel Farage's mind

Ukip leader casts a line to the disaffected
Who is bombing whom in the Middle East? It's amazing they don't all hit each other

Who is bombing whom in the Middle East?

Robert Fisk untangles the countries and factions
China's influence on fashion: At the top of the game both creatively and commercially

China's influence on fashion

At the top of the game both creatively and commercially
Lord O’Donnell: Former cabinet secretary on the election and life away from the levers of power

The man known as GOD has a reputation for getting the job done

Lord O'Donnell's three principles of rule
Rainbow shades: It's all bright on the night

Rainbow shades

It's all bright on the night
'It was first time I had ever tasted chocolate. I kept a piece, and when Amsterdam was liberated, I gave it to the first Allied soldier I saw'

Bread from heaven

Dutch survivors thank RAF for World War II drop that saved millions
Britain will be 'run for the wealthy and powerful' if Tories retain power - Labour

How 'the Axe' helped Labour

UK will be 'run for the wealthy and powerful' if Tories retain power
Rare and exclusive video shows the horrific price paid by activists for challenging the rule of jihadist extremists in Syria

The price to be paid for challenging the rule of extremists

A revolution now 'consuming its own children'
Welcome to the world of Megagames

Welcome to the world of Megagames

300 players take part in Watch the Skies! board game in London
'Nymphomaniac' actress reveals what it was really like to star in one of the most explicit films ever

Charlotte Gainsbourg on 'Nymphomaniac'

Starring in one of the most explicit films ever
Robert Fisk in Abu Dhabi: The Emirates' out-of-sight migrant workers helping to build the dream projects of its rulers

Robert Fisk in Abu Dhabi

The Emirates' out-of-sight migrant workers helping to build the dream projects of its rulers
Vince Cable interview: Charging fees for employment tribunals was 'a very bad move'

Vince Cable exclusive interview

Charging fees for employment tribunals was 'a very bad move'
Iwan Rheon interview: Game of Thrones star returns to his Welsh roots to record debut album

Iwan Rheon is returning to his Welsh roots

Rheon is best known for his role as the Bastard of Bolton. It's gruelling playing a sadistic torturer, he tells Craig McLean, but it hasn't stopped him recording an album of Welsh psychedelia
Morne Hardenberg interview: Cameraman for BBC's upcoming show Shark on filming the ocean's most dangerous predator

It's time for my close-up

Meet the man who films great whites for a living
Increasing numbers of homeless people in America keep their mobile phones on the streets

Homeless people keep mobile phones

A homeless person with a smartphone is a common sight in the US. And that's creating a network where the 'hobo' community can share information - and fight stigma - like never before