Objective: To determine gene(s) disrupted in a patient with partial frontal lobe epilepsy and cognitive impairment with concomitant de novo balanced chromosomal translocation t(2;13)(q24;q31). Design: Fluorescence in situ hybridization and array comparative genomic hybridization were used to map the locations of chromosomal translocation breakpoints. Results: SLC4A10 (OMIM 605556), a sodium bicarbonate transporter gene with high expression in the cerebral cortex and hippocampus, was disrupted by the translocation breakpoint on chromosome 2q24. The breakpoint on chromosome 13q31 was in a 1-megabase (Mb)-gene desert. Genomewide array comparative genomic hybridization confirmed the absence of additional chromosomal abnormalities. Conclusion: SLC4A10 is the third SLC4 base transporter family member to be implicated in human cognition and epilepsy.