The genes of two group III metabotropic glutamate receptors, mGluR7 and 8, are candidate susceptibility genes for epilepsy. The Tyr433Phe polymorphism of mGluR7 and a novel polymorphism in the mGluR8 gene located 29 bp after the termination codon (2756C/T) were investigated in case control association studies performed on DNA from more than 100 patients with idiopathic generalised epilepsy (IGE). No significant association was found with IGE for either polymorphism.