Reading and writing are crucial life skills but roughly one in ten children are affected
by dyslexia, which can persist into adulthood. Family studies of dyslexia suggest
heritability up to 70%, yet few convincing genetic markers have been found. Here we
performed a genome-wide association study of 51,800 adults self-reporting a dyslexia
diagnosis and 1,087,070 controls and identified 42 independent genome-wide significant
loci: 15 in genes linked to cognitive ability/educational attainment, and 27 new and
potentially more specific to dyslexia. We validated 23 loci (13 new) in independent
cohorts of Chinese and European ancestry. Genetic etiology of dyslexia was similar
between sexes, and genetic covariance with many traits was found, including ambidexterity,
but not neuroanatomical measures of language-related circuitry. Dyslexia polygenic
scores explained up to 6% of variance in reading traits, and might in future contribute
to earlier identification and remediation of dyslexia.
