Roundabout homolog 1 is a protein that in humans is encoded by the ROBO1 gene.[5][6][7]
Bilateral symmetric nervous systems have special midline structures that establish a partition between the two mirror image halves. Some axons project toward and across the midline in response to long-range chemoattractants emanating from the midline. The protein encoded by ROBO1 is structurally similar to a Drosophila integral membrane protein which is encoded by the Drosophila roundabout gene (a member of the immunoglobulin gene superfamily) and is both an axon guidance receptor and a cell adhesion receptor, known to be involved in the decision by axons to cross the central nervous system midline. Two transcript variants encoding different isoforms have been found for ROBO1.[7]
ROBO1 was implicated in a communication disorder based on a Finnish pedigree with severe dyslexia. Analyses revealed a translocation had occurred disrupting ROBO1.[8] Study of the phonological memory component of the language acquisition system suggests that ROBO1 polymorphisms are associated with functioning in this system.[9] The gene is thought to be related to the brain's ability to represent quantities, and is correlated with better math scores of young children in one limited study.[10]