Association of GSTT1 and GSTM1 polymorphisms in South Indian Epilepsy Patients.

Experimental studies suggest that oxidative stress is one of the contributing factors in the onset of epileptic seizures. Glutathione S-transferases (GSTs) are able to conjugate electrophilic compounds, and thus possess neuroprotective role by removing exogenous and endogenous oxidants, detoxifying therapeutic drugs, environmental toxins through conjugation with glutathione (GSH). Several studies from different ethnic groups showed that polymorphisms of the GST gene have been associated with Epilepsy. In the present study, we investigated the association of GST polymorphism in the South Indian epilepsy patients population. A total 371 samples (110 cases and 261 controls) were genotyped for the GST1 and GSTM1 polymorphism by multiplex PCR method. We observed a significant association of GSTT1 null polymorphism in patients with epilepsy. The frequency of the GSTT1 null genotype was found to be significantly higher in cases (35.45 %) than the controls (18.39 %) (OR: 2.44, 95%CI: 1.4-4.02, P <0.0001). In contrast, the frequency of the GSTM1 null variant was significantly lower in cases (11.81%) than controls (32.95%) (OR: 0.27, 95%CI: 0.14-0.51, P <0.001) indicating a protective role. These results indicated that individuals who have GSTT1 null variant are at higher risk for developing seizure than those of GSTT1 wild genotype. On the other hand, individuals carrying GSTM1 null variant showed protective role against seizure. Further, these two null variants did not show any significant association with antiepileptic drug-induced skin rash.