More has been revealed about the genes relating to dyslexia, with researchers identifying 42 genetic variants associated with the disorder.
It’s known the development of dyslexia can be partly due to genetic factors and tends to run in families, but there was not much knowledge on the specific genes responsible for it.
This was the largest genetic study of dyslexia and was led by the University of Edinburgh, involving over 50,000 adults who have been diagnosed and over a million other adults who have not. Past studies that have linked the disorder to specific genes were done with a small number of families and the research team says their evidence was unclear.
The researchers tested millions of genetic variants and their link with dyslexia status, finding 42 significant variants. 15 of those variants had already been linked with cognitive ability and educational attainment but the other 27 are newly identified.
Genetic correlations between dyslexia and other traits were found that included having ADHD, heightened pain sensitivity, and equal use of right and left hands.
“Our findings show that common genetic differences have very similar effects in boys and girls, and that there is a genetic link between dyslexia and ambidexterity,” said the lead researcher Michelle Luciano.
“Our results also suggest that dyslexia is very closely genetically related to performance on reading and spelling tests, reinforcing the importance of standardised testing in identifying dyslexia.”
Some of the genetic variants are related to other neurodevelopment conditions such as language delay, and with thinking skills and academic achievement. It was also found from the Chinese-speaking participants in the study that the general thinking processes for learning to read are not dependent on a particular language.
Luciano said there are currently no direct implications for people with the disorder, but these results offer more scientists more insight into the biology behind dyslexia.
“We can follow up the significant genes to see what their function is and how it might relate to the cognitive processes involved in reading and spelling,” she said.
The research was published in the journal Nature Genetics on October 20th.