Featured Research

from universities, journals, and other organizations

New form of intellectual disability discovered

Date:
April 27, 2012
Source:
Centre for Addiction and Mental Health
Summary:
Researchers have discovered a gene for a new form of intellectual disability, as well as how it likely affects cognitive development by disrupting neuron functioning.

Researchers at the Centre for Addiction and Mental Health (CAMH) led a study discovering a gene for a new form of intellectual disability, as well as how it likely affects cognitive development by disrupting neuron functioning.

CAMH Senior Scientist Dr. John Vincent and his team found a mutation in the gene NSUN2 among three sisters with intellectual disability, a finding to be published in the May issue of the American Journal of Human Genetics.

The discovery was made after mapping genes in a Pakistani family, in which three of seven siblings had intellectual disability as well as muscle weakness and walking difficulties, says Dr. Vincent, who heads the Molecular Neuropsychiatry and Development Laboratory in the Campbell Family Mental Health Research Institute at CAMH.

Intellectual disability is a condition in which individuals have limitations in their mental abilities and in functioning in daily life. It affects one to three per cent of the population, and is often caused by genetic mutations.

Another study in the same journal, submitted together with the CAMH-led research, also identified NSUN2 gene mutations in Iranian and Kurdish families with intellectual disability. As with the Pakistani family, first cousin marriages in these families carrying the mutations increased the likelihood of intellectual disability among their children, and enabled researchers to focus on areas to map genes.

"The combined results from these two studies mean that NSUN2 is among the most common causes of intellectual disability resulting from recessive genes," says Dr. Vincent.

As a recessive disorder, a child must inherit one defective NSUN2 gene from each parent to develop intellectual disability. This gene, located on chromosome 5p, encodes a type of protein called an RNA methyltransferase.

At the cellular level, the researchers found that the mutated protein was prevented from reaching its target area within the nucleus of a cell. As a result, it was unable to perform its normal role in cell division and/or RNA methylation.

Collaborators from the Wellcome Trust Centre for Stem Cell Research in Cambridge, U.K., showed which type of brain cells were likely to be most affected by this mutation. They are called Purkinje cells, a type of neuron that responds to the neurotransmitter GABA. Purkinje cells also control motor coordination, which were affected in the Pakistani family.

"We speculate that the muscle effects may result from the accumulation of the NSUN2 protein outside its target area in the nucleus," says Dr. Vincent.

To date, Dr. Vincent's lab has identified five genes causing different forms of recessive intellectual disability.

This research was supported by grants from Pakistan's Higher Education Commission and the Canadian Institutes of Health Research.


Story Source:

The above story is based on materials provided by Centre for Addiction and Mental Health. Note: Materials may be edited for content and length.


Journal Reference:

  1. MuzammilAhmad Khan, MuhammadArshad Rafiq, Abdul Noor, Shobbir Hussain, JoanaV. Flores, Verena Rupp, AkshitaK. Vincent, Roland Malli, Ghazanfar Ali, FalakSher Khan, GiseleE. Ishak, Dan Doherty, Rosanna Weksberg, Muhammad Ayub, Christian Windpassinger, Shahnaz Ibrahim, Michaela Frye, Muhammad Ansar, JohnB. Vincent. Mutation in NSUN2, which Encodes an RNA Methyltransferase, Causes Autosomal-Recessive Intellectual Disability. The American Journal of Human Genetics, 2012; DOI: 10.1016/j.ajhg.2012.03.023

Cite This Page:

Centre for Addiction and Mental Health. "New form of intellectual disability discovered." ScienceDaily. ScienceDaily, 27 April 2012. <www.sciencedaily.com/releases/2012/04/120427100111.htm>.
Centre for Addiction and Mental Health. (2012, April 27). New form of intellectual disability discovered. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2012/04/120427100111.htm
Centre for Addiction and Mental Health. "New form of intellectual disability discovered." ScienceDaily. www.sciencedaily.com/releases/2012/04/120427100111.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
WHO: Ebola Vaccine Trials to Start a in January

WHO: Ebola Vaccine Trials to Start a in January

AP (Oct. 21, 2014) Tens of thousands of doses of experimental Ebola vaccines could be available for "real-world" testing in West Africa as soon as January as long as they are deemed safe in soon to start trials, the World Health Organization said Tuesday. (Oct. 21) Video provided by AP
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins