Dyslexia: Causes

Pathogenesis (development of disease)

Dyslexia represents a very complex underlying disorder in which various causes may be present. However, genetic factors are always thought to interact with environmental factors. Up to 70% of dyslexia is genetic.

Etiology (causes)

Biographical causes

  • Genetic burden from parents, grandparents – children of dyslexics have a greatly increased risk of having dyslexia themselves (circa 50% for one parent, significantly higher for both parents)
    • Genetic risk dependent on gene polymorphisms:
      • Genes/SNPs (single nucleotide polymorphism):
        • Genes: DCDC2, TDP2
        • SNP: rs807701 in the gene DCDC2
          • Allele constellation: CT (1.88-fold).
          • Allele constellation: CC (2.0-fold to 5.0-fold)
        • SNP: rs2143340 in gene TDP2
          • Allele constellation: CT (slightly increased risk).
          • Allele constellation: CC (2.0-fold

Disease-related causes

Eyes and eye appendages (H00-H59).

  • Visual perception disorders, unspecified

Other

  • Disturbances in the perception of speech and processing of sounds.