Dyslexia may represent the first example of a LD whereby a possible pathway may link the observed behavior to an underlying neurological substrate that has a neurodevelopmental history beginning with an abnormal gene. Similar efforts are being made to link other cognitive disorders of development to a molecular pathway involved in brain development. The objective is to disclose a developmental brain pathway leading to a brain that has a particular structure and physiology, a set of perceptual, cognitive, and metacognitive associations, and a behavior explained by these cognitive structures and processes. Environments and learning are apt to play their respective roles, but their full impact can only be understood in terms of the brain they impinge upon. Advances in neuroimaging research, including functional imaging and the new tract tracing techniques, will link specific behavioral phenotypes to areas of abnormal activation and, hopefully, specific mutations. Finally, improved classification on the basis of identified gene mutations, brain activation patterns, and behavioral phenotypes will trigger the design and testing of specific therapies implemented at earlier and earlier stages of development, with the promise of much improved success for the expression of each child's full potential.