Study finds large proportion of intellectual disability is not genetically inherited
New research published Online First in The Lancet suggests that a high proportion of severe intellectual disability results from genetic causes that are not inherited. These findings are good news for parents, indicating a low risk of passing on the disorder to further children.
Intellectual disability affects between 1% and 2% of children worldwide. Although a handful of genes that appear to cause some cases of intellectual disability have been identified, the genetic causes of the disorder in most people remains unclear, especially those with non-syndromic types which have no obvious physical signs and cause up to 50% of intellectual disability worldwide.
Some evidence suggests that de novo (new) mutations, that show up for the first time in affected children but are not found in their parents, might be a common cause of the disorder.
As a joint effort by the German Mental Retardation Network led by André Reis from the Institute of Human Genetics, University of Erlangen-Nuremberg, Germany, the current study used a new technique known as exome sequencing to look for mutations that are not inherited but newly formed in 51 children with unexplained severe non-syndromic intellectual disability (an IQ <50) and their unaffected parents from nine centres across Germany and one center from Switzerland.
The researchers found that children with intellectual disability carried a significantly higher number of likely disease-causing mutations in their genome than those without the disorder. New mutations in both 11 known and six new candidate genes were estimated to cause intellectual disability in up to 55% of the cases studied.
"Although believed to be relatively common in intellectual disability, these results suggest that only a small proportion of cases of sporadic intellectual disability are likely to be inherited in autosomal recessive fashion (affected children inherit one copy of the faulty gene mutation from each parent)", explains Reis.
Writing in a linked Comment, Jozef Gecz and Eric Haan from the University of Adelaide in Australia point out, "Copy number variant profiling and whole-exome sequencing should resolve most (>60%) cases of severe intellectual disability. The remaining cases might be more complex, with contributions from multiple genes, environmental factors, or mutations in non-coding regions of the genome. Whole-genome sequencing technology has the potential to become the first-line diagnostic test for many disorders, and particularly intellectual disability."
More information: www.thelancet.com/… 0-9/abstract
Journal reference: The Lancet
Provided by Lancet
- Intellectual disability is frequently caused by non-hereditary genetic problems Apr 18, 2011 | not rated yet | 0
- New genetic test for cause of intellectual disability to be launched Feb 26, 2010 | not rated yet | 0
- Gene identified as cause of some forms of intellectual disability Dec 15, 2009 | not rated yet | 0
- New gene for intellectual disability discovered Jul 15, 2011 | not rated yet | 0
- New form of intellectual disability discovered Apr 27, 2012 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
Researchers from Queen Mary, University of London have led the largest sequencing study of human disease to date, investigating the genetic basis of six autoimmune diseases.
Genetics May 22, 2013 | 4.5 / 5 (4) | 0 |
University of Minnesota Medical School researchers from the Masonic Cancer Center, University of Minnesota, in partnership with the University's Brain Tumor Program, have developed a new mouse model of malignant peripheral ...
Genetics May 20, 2013 | 5 / 5 (1) | 0 |
Northwestern University scientists have shown a gene involved in neurodegenerative disease also plays a critical role in the proper function of the circadian clock.
Genetics May 16, 2013 | 3 / 5 (1) | 1 |
Informed consent is the backbone of patient care. Genetic testing has long required patient consent and patients have had a "right not to know" the results. However, as 21st century medicine now begins to use the tools of ...
Genetics May 16, 2013 | 5 / 5 (1) | 3 |
Ethicists provide framework supporting new recommendations on reporting incidental findings in gene sequencing
In a paper published in Science Express, a group of experts led by bioethicists in the Center for Medical Ethics and Health Policy at Baylor College of Medicine provide a framework for the new American College of Medical Geneti ...
Genetics May 16, 2013 | not rated yet | 0
Artemio Martinez balanced his corpulent frame on a stool in a Mexico City street taco stand, downing a sweet soda and eating a final pork-filled corn tortilla.
44 minutes ago | not rated yet | 0
The World Health Organization voiced deep concern Thursday over the SARS-like virus that has killed 22 people in less than a year, saying it might potentially spread more widely between humans.
29 minutes ago | 5 / 5 (1) | 0
(AP)—Researchers examining the incidence of brain cancer at jet engine manufacturer Pratt & Whitney in Connecticut say they have found no statistically significant elevations in the rate of cancer among workers.
19 minutes ago | not rated yet | 0
(Medical Xpress)—Regulating the distribution of power in neurons is done by a system that makes the national electric grid look simple by comparison. Each neuron has several thousand mitochondria confined ...
13 hours ago | 4.8 / 5 (6) | 0 |
The British Menopause Society and Women's Health Concern have today released updated guidelines on Hormone Replacement Therapy (HRT) to provide clarity around the role of HRT, the benefits and the risks. The new guidelines ...
2 hours ago | not rated yet | 0
A brief visual task can predict IQ, according to a new study. This surprisingly simple exercise measures the brain's unconscious ability to filter out visual movement. The study shows that individuals whose ...
18 hours ago | 4.5 / 5 (10) | 1 |