- Glutamate receptor, ionotropic, N-methyl D-aspartate 2A (GRIN2A) gene as a positional candidate for attention-deficit/hyperactivity disorder in the 16p13 region. Adams, J., Crosbie, J., Wigg, K., Ickowicz, A., Pathare, T., Roberts, W., Malone, M., Schachar, R., Tannock, R., Kennedy, J.L., Barr, C.L. Mol. Psychiatry (2004)