Seizure-related 6,a brain-specific expression gene,is highly expressed in the human cerebellum

Epilepsy is a complex, Mendelian disease, and most cases are sporadic. Genomic comparisons of tissue from identified monogenic epilepsies with multigenic and acquired syndromes could ultimately reveal crucial molecular neuropathology for an epileptic phenotype. In the present study, a novel gene, human seizure-related (hSEZ)-6, was isolated from a human brain cDNA library. hSEZ-6 comprises 17 exons and spans a region of at least 55.6 kb, which was localized to 17q12 by radiation hybridization. hSEZ-6 exhibits two isoform types, hSEZ-6A and hSEZ-6B, which encode 996 and 995 amino acids, respectively. The two putative hSEZ-6 proteins contain similar motifs and share 82% and 84% identity with mouse SEZ-6A protein, whose expression level increased in mouse cerebral cortex-derived cells treated with a convulsant drug, pentylentetrazole. Northern blot analysis demonstrated that hSEZ-6 is expressed highly in the cerebellum and in nucleus of the extrapyramidal system, such as the caudate nucleus and putamen. Reverse transcription polymerase chain reaction revealed that hSEZ-6 is expressed in neurons rather than gliocytes, which suggests that hSEZ-6 is a seizure-related gene.