Association of BRD2 polymorphisms with photoparoxysmal response

A trait locus for electroencephalographic photoparoxysmal response (PPR) has been mapped to the chromosomal region 6p21 near a susceptibility locus for juvenile myoclonic epilepsy (JME). Linkage disequilibrium mapping revealed strong associations between JME and polymorphisms of the gene encoding the bromodomain-containing protein 2 (BRD2). The present association study tested whether genetic variation of BRD2 confers also susceptibility to PPR. All study participants were of German descent, comprising 187 subjects exhibiting PPR (types I–IV) and 666 healthy controls. Genotypes of each study participant were assessed for seven single nucleotide polymorphisms and one dinucleotide repeat polymorphism, covering the genomic BRD2 sequence. Allelic and haplotypic associations were found between PPR and six BRD2 polymorphisms (P: 0.0075–0.035). Considering the strong neurobiological association of JME and PPR, the present results support evidence that PPR and JME share epileptogenic pathways, for which BRD2 might be an underlying susceptibility gene.