A Deep Dive into the Genetics of Dyslexia

Dyslexia is a form of neurodivergence that impacts hundreds of millions of people worldwide. Dyslexia can make reading, learning, and daily living a massive challenge. Dyslexia impacts people regardless of what language(s) they speak, their age, or their education level. Like other types of neurodivergence, dyslexia occurs as a combination of genetic, developmental, and environmental factors. Similarly to autism spectrum disorder, dyslexia has a large heritable component, meaning the specific variants of genes that you have will increase your chances of having it. Here we will discuss the genes that impact dyslexia and the impact dyslexia has on people worldwide. 

Dyslexia is a complex neuropsychological condition

Unsurprisingly, dyslexia is approximately 50% heritable, meaning that 50% of your likelihood of getting dyslexia comes from variants of genes you inherited from your parents. This translates to dyslexia running in families; if one of your parents has dyslexia, you are 50% likely to have it as well (Dyslexia Research Trust, n.d.). Due in part to dyslexia running in families, it is estimated to impact three to 17% of the worldwide population. Dyslexia is also more common in people assigned male at birth, making its inheritance partially sex-related (Erbeli et al., 2021). Similarly, ambidextrous individuals and left-handed individuals are more likely to have dyslexia. This is because a weak or no preference for a hand while writing can lead to dyslexia; motor skills and reading/writing skills are linked (Dyslexia Research Trust, n.d.). 

Dyslexia impacts your reading, writing, and fine motor skills

Dyslexia genome-wide association studies (GWAS) have, unfortunately, not yielded much information (Dyslexia Research Trust, n.d.). Genome-wide association studies look for SNPs, or one-base-pair differences, in someone’s entire genetic makeup that are consistently present in people with the same condition (“Genome-wide association study”, 2025). Despite this, multiple specific genes that contribute to dyslexia have been identified. We each have the same set of genes, so having different variants or SNPs will increase your dyslexia risk.

1. KIAA1039

   1. This gene is located on chromosome 6

   2. It is important in early brain development

   3. The function of this gene is impaired by up to 40% in people with dyslexia (Dyslexia Research Trust, n.d.)

   4. The variants in KIAA1039 that cause dyslexia remain unidentified (Dennis et al., 2009)

2. DYX1C1 

   1. This gene is located on chromosome 15

   2. This was the first gene to be identified that impacts dyslexia

   3. This gene is more common in people of Finnish ancestry (Dyslexia Research Trust, n.d.)

   4. -3A and 1249T variants increase your dyslexia likelihood (Taipale et al., 2003)

3. ROBO1

   1. Unknown which variants increase dyslexia risk

4. DCDC2

   1. Unknown which variants increase dyslexia risk

   
   
   
   

   

   SNPs appear as point mutations in a gene

Dyslexia can be an incredibly challenging condition to live with. People with dyslexia can struggle with organization, interpreting directions, increased mental tiredness, self-esteem, and short-term memory (British Dyslexia Association, n.d.). It is important to be empathetic to and understanding of their struggles and their needs; patience and actively listening to your loved ones with dyslexia can help. If you or a loved one has dyslexia and you are wondering about the genetic impact dyslexia might have within your family, speaking with a physician and a genetic counselor can help identify if and how your genes might contribute to your dyslexia.  

Works Cited

British Dyslexia Association. (n.d.). Living with a dyslexic partner. British Dyslexia Association - Adults; British Dyslexia Association. Retrieved May 31, 2025, from https://www.bdadyslexia.org.uk/advice/adults/living-with-a-dyslexic-partner

Dennis, M. Y., Paracchini, S., Scerri, T. S., Prokunina-Olsson, L., Knight, J. C., Wade-Martins, R., Coggill, P., Beck, S., Green, E. D., & Monaco, A. P. (2009). A Common Variant Associated with Dyslexia Reduces Expression of the KIAA0319 Gene. PLoS Genetics, 5(3), e1000436. PubMed. https://doi.org/10.1371/journal.pgen.1000436

Dyslexia Research Trust Contributors. (n.d.). Genetics of Dyslexia | Dyslexia Research Trust. DRT Research; Dyslexia Research Trust. Retrieved May 31, 2025, from https://www.dyslexic.org.uk/genetics-of-dyslexia

Erbeli, F., Rice, M., & Paracchini, S. (2021). Insights into Dyslexia Genetics Research from the Last Two Decades. Brain Sciences, 12(1), 27. PubMed. https://doi.org/10.3390/brainsci12010027

Taipale, M., Kaminen, N., Nopola-Hemmi, J., Haltia, T., Myllyluoma, B., Lyytinen, H., Muller, K., Kaaranen, M., Lindsberg, P. J., Hannula-Jouppi, K., & Kere, J. (2003). A candidate gene for developmental dyslexia encodes a nuclear tetratricopeptide repeat domain protein dynamically regulated in brain. Proceedings of the National Academy of Sciences, 100(20), 11553–11558. PNAS. https://doi.org/10.1073/pnas.1833911100

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