A study of 50,000 people and published in “Nature Genetics” has for the first time identified a large number of genes that are reliably associated with dyslexia
About a third of the 42 gene variants identified have previously been linked to general cognitive ability and educational performance.
The researchers say their findings help understand biology that explains why some children have trouble reading or spelling.
Dyslexia is known to run in families, in part due to genetic factors, but until now little was known about the specific genes associated with the risk of developing it.
The study, led by the University of Edinburgh, is the largest genetic study of dyslexia to date. Previous studies linking dyslexia to specific genes had been conducted in a small number of families and the evidence was unclear, the research team says.
In this have participated more than 50,000 adults who have been diagnosed with dyslexia and more than a million adults who have not.
The researchers analyzed the association between millions of genetic variants with dyslexia status and found 42 significant variants.
Some of them are associated with other neurodevelopmental conditions, such as language delay, and thinking skills and academic performance. Many, however, are novel and could represent genes that are more specifically associated with processes essential for learning to read.
Many of the genes associated with dyslexia are also associated with attention deficit hyperactivity disorder. Much less overlap of dyslexia-associated genes was found for psychiatric, lifestyle, and health conditions.
There is a genetic link between dyslexia and ambidexterity
The researchers were able to predict the reading and spelling ability of children and adults from four other research studies using the study’s genetic information, but not with the accuracy needed for diagnostic use.
Lead researcher Michelle Luciano, from the University of Edinburgh’s School of Philosophy, Psychology and Language Sciences, says the study sheds light on many unanswered questions surrounding dyslexia.
‘Our results show that common genetic differences have very similar effects in boys and girls, and that there is a genetic linktico between dyslexia and ambidestreza», says Lucian. ‘Previous work suggested that some brain structures might be altered in people with dyslexia, but we found no evidence that genes explain this.’
“Our results also suggest that the dyslexia is closely related genetically to performance in the tests of reading and spellingwhich reinforces the importance of standardized tests to identify it».