First gene link seen to contested child disorder

For years, they have been dumped at the back of the class, the pupils who are impulsive, hyperactive and unable to concentrate - in short, a waste of a teacher's time.

Their parents, too, have often been branded as failures, as duds who let their children become unruly through poor discipline or a diet of junk-food and telly.

But a growing body of opinion has been pleading for tolerance.

Such children, they argue, are not cases of bad behaviour or poor parenting but kids with a genuine medical condition: attention-deficit hyperactivity disorder, or ADHD.

These campaigners have now gained a massive boost, for a new study has uncovered the first direct evidence that ADHD has, at least partially, a genetic cause.

The evidence, published online on Thursday in the medical journal The Lancet by British specialists, derives from a comparison of the genetic code of 366 children with ADHD and 1,047 without it.
The trawl brought up telltale differences between the two groups.

The ADHD children were likelier to have small but important segments of DNA that were either missing or duplicated in their genome compared to the "control" group.

These segments, known as copy number variations (CNVs), play an important role, acting rather like a control valve over genes, which make the body's all-important proteins. If CNVs are missing or duplicated, they can alter the dosage of genes by 50 percent, up or down.

"We've known for many years that ADHD may well be genetic because it tends to run in families in many instances. What's really exciting is that we've found the first direct genetic link," said Anita Thapar, a professor of neuropsychiatric genetics at Cardiff University, Wales.

Even more intriguing is the discovery that these CNVs appear to cluster in key areas, notably in Chromosome 16, that overlap with regions implicated in autism and schizophrenia - two other enigmatic, but now firmly acknowledged, brain disorders.

"ADHD can be stigmatising because there's a lot of public misunderstanding about it," Thapar said in a press conference webcast from London.

"For example, some people say it's not a real disorder or it's the result of bad parenting, and parents and children can encounter much stigma because of this. So finding this direct genetic link to ADHD should help clear this misunderstanding and address this stigma."

Despite the discovery, a long road lies ahead before ADHD is fully understood and a cure for the condition emerges, the authors caution. At present, ADHD is tackled by hefty medication and behavioural exercises.

"ADHD is not caused by a single genetic change but is likely caused by a number of genetic changes, including CNVs, interacting with as-yet unidentified environmental factors," said fellow researcher Kate Langley.

"Screening children for the CNVs that we have identified will not help diagnose their condition. We already have very rigorous clinical assessments to do just that."

ADHD affects around one in 50 children, according to some estimates. The condition can be crippling, for it can badly affect a child's education and ability to forge relationships.

Until now, the genetic link had been statistical or anecdotal, but not born out by direct evidence. For instance, it was found that in identical twins, if one child had ADHD, the other had a 75 percent chance of having it.

ri/co

Sport
sportSo, how closely were you paying attention during 2014?
Arts and Entertainment
Dennis speaks to his French teacher
tvThe Boy in the Dress, TV review
News
One father who couldn't get One Direction tickets for his daughters phoned in a fake bomb threat and served eight months in a federal prison
people... (and one very unlucky giraffe)
Arts and Entertainment
Joel Edgerton, John Turturro and Christian Bale in Exodus: Gods and Kings
film
PROMOTED VIDEO
Life and Style
ebookNow available in paperback
ebooks
ebookPart of The Independent’s new eBook series The Great Composers
News
i100
Arts and Entertainment
The Plaza Theatre in Atlanta, Georgia was one of the 300 US cinemas screening
filmTim Walker settles down to watch the controversial gross-out satire
Arts and Entertainment
Amy Adams and Christoph Waltz in Tim Burton's Big Eyes
film reviewThis is Tim Burton’s most intimate and subtle film for a decade
Life and Style
Mark's crab tarts are just the right size
food + drinkMark Hix cooks up some snacks that pack a punch
Arts and Entertainment
Jack O'Connell stars as Louis Zamperini in Angelina Jolie's Unbroken
film review... even if Jack O'Connell is excellent
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating
    and  

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

    iJobs Job Widget
    iJobs General

    Selby Jennings: VP/SVP Credit Quant- NY- Investment Bank

    Not specified: Selby Jennings: VP/SVP Credit Quant Top tier investment bank i...

    Ashdown Group: Senior Marketing Executive- City of London, Old Street

    £40000 - £43000 per annum + benefits: Ashdown Group: Senior Marketing Executiv...

    Ashdown Group: Marketing Manager

    £40000 - £43000 per annum + benefits: Ashdown Group: An international organisa...

    Ashdown Group: Internal Recruiter -Rugby, Warwickshire

    £25000 - £30000 per annum: Ashdown Group: Internal Recruiter -Rugby, Warwicksh...

    Day In a Page

    Aren’t you glad you didn’t say that? The worst wince-and-look-away quotes of the year

    Aren’t you glad you didn’t say that?

    The worst wince-and-look-away quotes of the year
    Hollande's vanity project is on a high-speed track to the middle of nowhere

    Vanity project on a high-speed track to nowhere

    France’s TGV network has become mired in controversy
    Sports Quiz of the Year

    Sports Quiz of the Year

    So, how closely were you paying attention during 2014?
    Alexander Armstrong on insulting Mary Berry, his love of 'Bargain Hunt', and life as a llama farmer

    Alexander Armstrong on insulting Mary Berry and his love of 'Bargain Hunt'

    From Armstrong and Miller to Pointless
    Sanchez helps Gunners hold on after Giroud's moment of madness

    Sanchez helps Gunners hold on

    Olivier Giroud's moment of madness nearly costs them
    A Christmas without hope: Fears grow in Gaza that the conflict with Israel will soon reignite

    Christmas without hope

    Gaza fears grow that conflict with Israel will soon reignite
    After 150 years, you can finally visit the grisliest museum in the country

    The 'Black Museum'

    After 150 years, you can finally visit Britain's grisliest museum
    No ho-ho-hos with Nick Frost's badass Santa

    No ho-ho-hos with Nick Frost's badass Santa

    Doctor Who Christmas Special TV review
    Chilly Christmas: Swimmers take festive dip for charity

    Chilly Christmas

    Swimmers dive into freezing British waters for charity
    Veterans' hostel 'overwhelmed by kindness' for festive dinner

    Homeless Veterans appeal

    In 2010, Sgt Gary Jamieson stepped on an IED in Afghanistan and lost his legs and an arm. He reveals what, and who, helped him to make a remarkable recovery
    Isis in Iraq: Yazidi girls killing themselves to escape rape and imprisonment by militants

    'Jilan killed herself in the bathroom. She cut her wrists and hanged herself'

    Yazidi girls killing themselves to escape rape and imprisonment
    Ed Balls interview: 'If I think about the deficit when I'm playing the piano, it all goes wrong'

    Ed Balls interview

    'If I think about the deficit when I'm playing the piano, it all goes wrong'
    He's behind you, dude!

    US stars in UK panto

    From David Hasselhoff to Jerry Hall
    Grace Dent's Christmas Quiz: What are you – a festive curmudgeon or top of the tree?

    Grace Dent's Christmas Quiz

    What are you – a festive curmudgeon or top of the tree?
    Nasa planning to build cloud cities in airships above Venus

    Nasa planning to build cloud cities in airships above Venus

    Planet’s surface is inhospitable to humans but 30 miles above it is almost perfect