A glutamate binding subunit gene, GRINA, has been previously mapped to human chromosome 8. A form of inherited epilepsy, benign familial neonatal convulsions (BFNC), has also been localized to chromosome 8. As NMDA receptors have been implicated in the pathogenesis of epilepsy, we were interested in determining whether GRINA mapped to the same region of chromosome 8 as BFNC. Fluorescence in situ hybridization localized GRINA to band 8q24, distal to the thyroglobulin gene. The strongest signal was seen at 8q24.3. A panel of 97 radiation hybrids (RH) was used to verify the localization. The RH mapping results placed GRINA as the most telomeric marker on our map of 8q24, distal to the interval defined for BFNC.