Mutations in GABRG2 receptor gene are not a major factor in the pathogenesis of mesial temporal lobe epilepsy in Indian population.
OBJECTIVE
This study is focused on GABRG2 gene sequence variations in patients with mesial temporal lobe epilepsy (mTLE). The GABAAreceptor is a heteropentameric receptor and alpha-1 beta-2 gamma-2 subunits combination is most abundant and present in almost all regions of the brain. The gamma-2 subunit (GABRG2) gene mutations have been reported in different epilepsy pathologies. In the present study we have looked for GABRG2 gene sequence variations in patients with mTLE.


METHODS
Twenty patients (12 females and eight males, age 4.6-38 years) with MTLE were recruited for this investigation. Patients were recommended for epilepsy surgery after all clinical investigations as per the epilepsy protocol. Ethnically matched glioma or meningioma patients were considered as nonepileptic controls. During temporal lobectomy of amygdalohippocampectomy, hippocampal brain tissue samples were resected guided by intraoperative electrocorticography (ECoG) activity. All 11 exons of GABRG2 gene with their flanking intronic regions were amplified by polymerase chain reaction (PCR) and screened by DNA sequencing analysis for sequence variations.


METHODS
Comparison of allele frequencies between patient and control groups was determined using a c(2) test.


CONCLUSIONS
Total five DNA sequence variations were identified, three in exonic regions (c.643A > G, rs211035), (c.T > A, rs424740), and (c.C > T, rs418210) and two in intronic regions (c.751 + 41A > G, rs211034) and (c.751 + 52G > A, rs 34281163). Allele frequencies of variants identified in this study did not differ between patients and normal controls. Thus, we conclude that GABRG2 gene may not be playing significant role in the development of epilepsy or as a susceptibility gene in patients with MTLE in Indian population.
Center for Excellence in Epilepsy, A joint National Brain Research Centre-All Institute of Medical Sciences Collaboration, National Brain Research Centre, Manesar, Haryana, India.
Aparna Banerjee
AB
Dixit
Center for Excellence in Epilepsy, A joint National Brain Research Centre-All Institute of Medical Sciences Collaboration, National Brain Research Centre, Manesar, Haryana, India.
Jyotirmoy
J
Banerjee
Department of Neurosurgery, All Institute of Medical Sciences, New Delhi, India.
Abuzar
A
Ansari
Department of Neurology, All Institute of Medical Sciences, New Delhi, India.
Manjari
M
Tripathi
Department of Neurosurgery, All Institute of Medical Sciences, New Delhi, India.
Sarat P
SP
Chandra
Epilepsy; GABRG2 receptor; mutations