The biology of developmental dyslexia.

Dyslexia is a relatively common disorder that, when severe, persists into adulthood. New evidence suggests that females are affected nearly as frequently as males. Neuropsychological studies characterize dyslexia as a language disorder that involves phonological deficits in particular. Educational therapies aimed at direct improvement of reading skill constitute the best available treatment. Variable genetic transmission leading to a final common pathway appears to involve deficits in phonological coding. Postmortem studies and in vivo anatomical imaging suggest altered asymmetry of structures in the temporal lobes, and neuroimaging with positron emission tomography indicates left temporoparietal dysfunction in particular. Neuromaging is providing a window into the brain that promises further insights into the biology of dyslexia.