42 Genetic Variants Linked to Dyslexia

A gene study by researchers in Scotland has linked a series of DNA variants to dyslexia, a neurodevelopmental condition known to run in families and linked to difficulties with reading and spelling.  According to the team from University of Edinburgh, around one-third of the 42 genetic variants identified have been previously linked to general cognitive ability and educational attainment.

The work in Nature Genetics is the largest genetic study of dyslexia to date, involving more than 50,000 adults with dyslexia and more than one million adults without it. Previous studies linking dyslexia to specific genes have been done on small numbers of families, and the evidence was unclear.

The team tested the association between millions of genetic variants with dyslexia status and found 42 significant variants. Some are associated with other neurodevelopment conditions, such as language delay, and with thinking skills and academic achievement. Many, however, are novel and could represent genes that more specifically associate with processes essential for learning to read.

Many of the genes associated with dyslexia were also found to be associated with attention deficit hyperactivity disorder, while a much smaller overlap was found between dyslexia and other psychiatric, lifestyle and health conditions. Several of the associated genetic variants were also significant in a Chinese speaking sample, suggesting that there are general cognitive processes in learning to read that are not dependent on the type of language.

Researchers say they were also able to predict how well children and adults from four other research studies can read and spell using the genetic information from the study, but not with the accuracy needed for diagnostic use.

“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,” says lead researcher Michelle Luciano, of the University of Edinburgh’s School of Philosophy, Psychology and Language Sciences. “Previous work suggested some brain structures may be altered in people with dyslexia, but we did not find evidence that genes explain this.”

The results also suggest that dyslexia is very closely related genetically to performance on reading and spelling tests, reinforcing the importance of standardized testing in identifying dyslexia, Luciano adds.