Does Dyslexia Have a Genotype?

Although dyslexia research is abundant, a nagging question has remained: Is the condition hereditary?

Previous familial studies suggest a strong genetic predisposition, yet few markers have been identified to prove the correlation. To investigate further, an international team of researchers have conducted the largest genome-wide association (GWAS) study of dyslexia to date.

Led by the University of Edinburgh, UK, the study included 1,087,070 controls and 51,800 adults with a dyslexia diagnosis – selected from personal genetics company 23andMe (1). DNA samples were obtained from saliva and analyzed on a genotyping platform by the Nation Genetics Institute. A total of 42 genetic variants were found to be associated with dyslexia; of these, 15 have been previously linked to cognitive ability and educational attainment, but the remaining 27 were newly identified.

Several of the new variants were validated in a genomic study by the GenLang consortium of spelling and reading performance in English and other European languages.

The work also found a positive genetic link between dyslexia and ambidexterity, as well as a “moderate” genetic correlation between dyslexia and ADHD. In the future, researchers hope that the new variants will be prioritized for further investigation to increase our understanding of the biological mechanisms behind dyslexia and expand diagnostic capabilities.