Study Finds Large Proportion Of Intellectual Disability Is Not Genetically Inherited

Date: Oct-01-2012New 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 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."

Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.