Genetic studies reveal new causes of severe obesity in childhood

Dec 06, 2009

Scientists in Cambridge have discovered that the loss of a key segment of DNA can lead to severe childhood obesity. This is the first study to show that this kind of genetic alteration can cause obesity. The results are published today in Nature.

The study, led by Dr Sadaf Farooqi from the University of Cambridge and Dr Matt Hurles from the Wellcome Trust Sanger Institute, looked at 300 children with severe obesity.

The team scanned each child's entire genome looking for types of mutation known as copy number variants (CNVs). CNVs are large chunks of DNA either duplicated or deleted from our genes. Scientists believe this type of mutation may play an important role in genetic diseases.

By looking for CNVs that were unique in children with severe obesity, compared with over 7,000 controls (apparently healthy volunteers from the Wellcome Trust Case Control Consortium 2), they found that certain parts of the were missing in some patients with severe obesity.

According to Dr Farooqi: "We found that part of chromosome 16 can be deleted in some families, and that people with this deletion have severe obesity from a young age.

"Our results suggest that one particular gene on chromosome 16 called SH2B1 plays a key role in regulating weight and also in handling blood sugar levels. People with deletions involving this gene had a strong drive to eat and gained weight very easily."

Dr Matt Hurles adds: "This is the first evidence that copy number variants have been linked to a metabolic condition such as obesity. They are already known to cause other disorders such as autism and learning difficulties."

The findings also have implications for diagnosing severe , which has on occasion been misattributed to abuse. Some of the children in the study had been formally placed on the Social Services 'at risk' register on the assumption that the parents were deliberately overfeeding their children and causing their severe obesity. They have now been removed from the register.

"This study shows that is a serious medical issue that deserves scientific investigation," says Dr Farooqi. "It adds to the growing weight of evidence that a wide range of genetic variants can produce a strong drive to eat. We hope that this will alter attitudes and practices amongst those with professional responsibility for the health and well-being of children."

Obesity is increasing throughout the world and is now recognised as a major global public health concern. Although the increased prevalence of over the past 30 years is undoubtedly driven by environmental factors, genetic factors play a major role in determining why some people are more likely to gain weight than others.

More information: The paper, Elena G. Bochukova et al, 'Large, rare chromosomal deletions associated with severe early-onset obesity' is published in Nature on 6 December 2009.

Source: University of Cambridge (news : web)

Explore further: Low tolerance for pain? The reason may be in your genes

add to favorites email to friend print save as pdf

Related Stories

Gene produces hormones that lead to obesity

Jul 14, 2008

(PhysOrg.com) -- Obesity and common weight gain share a genetic basis. Professor Philippe Froguel, from Imperial College in Great Britain, and his team from the laboratoire Génomique et physiologie moléculaire des maladies ...

Mutant sperm guide clinicians to new diseases

Dec 02, 2007

Research published today in Nature Genetics shows that some rearrangements of the human genome occur more frequently than previously thought. The work is likely to lead to new identification of genes involved in disease and to ...

Influence of 'obesity gene' can be offset by healthy diet

Mar 03, 2009

Children who carry a gene strongly associated with obesity could offset its effect by eating a low energy density diet, according to new research from UCL (University College London) and the University of Bristol published ...

Recommended for you

Low tolerance for pain? The reason may be in your genes

4 hours ago

Researchers may have identified key genes linked to why some people have a higher tolerance for pain than others, according to a study released today that will be presented at the American Academy of Neurology's 66th Annual ...

Refining the language for chromosomes

Apr 17, 2014

When talking about genetic abnormalities at the DNA level that occur when chromosomes swap, delete or add parts, there is an evolving communication gap both in the science and medical worlds, leading to inconsistencies in ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

dirk_bruere
not rated yet Dec 07, 2009
When I was at school 40 years ago about 1% of the kids were obese. Where were all these genes then?

More news stories

Less-schooled whites lose longevity, study finds

Barbara Gentry slowly shifts her heavy frame out of a chair and uses a walker to move the dozen feet to a chair not far from the pool table at the Buford Senior Center. Her hair is white and a cough sometimes interrupts her ...

Cancer stem cells linked to drug resistance

Most drugs used to treat lung, breast and pancreatic cancers also promote drug-resistance and ultimately spur tumor growth. Researchers at the University of California, San Diego School of Medicine have discovered ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.