Genetics of dyslexia: the evolving landscape.

Dyslexia is among the most common neurodevelopmental disorders,
with a prevalence of 5–12%. At the phenotypic level, various
cognitive components that enable reading and spelling and that are
disturbed in affected individuals can be distinguished. Depending
on the phenotype dimension investigated, inherited factors are
estimated to account for up to 80%. Linkage findings in dyslexia
are relatively consistent across studies in comparison to findings
for other neuropsychiatric disorders. This is particularly true for
chromosome regions 1p34–p36, 6p21–p22, 15q21 and 18q11. Four
candidate genes have recently been identified through systematic
linkage disequilibrium studies in linkage region 6p21–p22, and
through cloning approaches at chromosomal breakpoints. Results
indicate that a disturbance in neuronal migration is a pathological
correlate of dyslexia at the functional level. This review presents
a summary of the latest insights into the genetics of dyslexia and
an overview of anticipated future developments.