This observation supports a previous report that a susceptibility locus for common idiopathic generalized epilepsy maps to chromosomal region 2q36 (Sander et al., 2002), which also includes SLC4A3. Indeed, in a subsequent study a common polymorphism within the coding sequence of SLC4A3, which entails the amino acid exchange Ala867Asp, was associated with an increased risk to develop idiopathic generalized epilepsy (Sander et al., 2002). This evidence concerns the gene SLC4A3 and juvenile myoclonic epilepsy.