Theories of developmental dyslexia differ on how to best interpret the great variety of symptoms (linguistic, sensory and motor) observed in dyslexic individuals. One approach views dyslexia as a specific phonological deficit, which sometimes co-occurs with a more general sensorimotor syndrome. This article on the neurobiology of dyslexia shows that neurobiological data are indeed consistent with this view, explaining both how a specific phonological deficit might arise, and why a sensorimotor syndrome should be significantly associated with it. This new conceptualisation of the aetiology of dyslexia could generalize to other neurodevelopmental disorders, and might further explain heterogeneity within each disorder and comorbidity between disorders.