BACKGROUND: Febrile seizure is the most common form of childhood seizure. Although its exact cause is unclear, many researchers emphasize the importance of its genetic predisposition. Recent genetic studies revealed the importance of the mutations of the gamma-aminobutyric acid A receptor as the etiology of the febrile seizures. R43Q mutation affecting the gamma 2-subunit N-terminal domain has been related to childhood absence epilepsy and febrile seizure. METHODS: We investigated R43Q mutations of the GABRG2 gene, located on the long arm of chromosome 5 encoding the gamma 2-subunit of the gamma-aminobutyric acid A receptor. We studied 44 patients with febrile seizure and 49 children without any febrile seizure who were admitted to our clinic. RESULTS: We found that 36% of our patient group, the children who experienced febrile convulsions, had heterozygous R43Q mutation. Statistical studies revealed that heterozygous R43Q mutation of gamma-aminobutyric acid A receptor gamma 2 subunit was higher in the study group than in the control group (P < 0.01). CONCLUSIONS: Heterozygous gamma-aminobutyric acid A receptor gamma 2 subunit (R43Q) mutation may have an effect in the development of febrile seizures.