Oxidative Stress in the Development of Genetic Generalised Epilepsy: An Observational Study in Southern Indian Population.

INTRODUCTION: Oxidative stress resulting from excessive generation of Reactive Oxygen Species (ROS) plays a significant role in neurodegeneration associated with seizures/epilepsy. AIM: To evaluate oxidative stress markers and antioxidant enzymes in Genetic Generalised Epilepsy (GGE) and to know the extent of oxidative stress induced by Anti-Epileptic Drugs (AEDs) with the time duration of treatment. MATERIALS AND METHODS: In this case-control study, 310 GGE patients (male:female=203:107), who were on AED treatment (n=235) and 75 untreated patients (male:female=49:26) along with 310 age and sex matched healthy controls were recruited. Oxidative stress markers such as Nitric Oxide (NO), Malondialdehyde (MDA) and antioxidant enzyme activities namely Superoxide Dismutase (SOD), Glutathione Peroxidase (GPx) and Catalase (CAT) were measured spectrophotometrically. RESULTS: Significantly higher levels of serum NO, MDA and low levels of plasma Total Antioxidant Capacity (TAC) were found in patients as compared to controls (p<0.001) whereas erythrocyte SOD, CAT and GPx activities were found to be significantly low in patients when compared to the control group (p<0.001). Statistically significant higher levels of NO, MDA and lower levels of SOD, CAT and TAC were observed in patients subgroup, who were on AEDs for more than >5 years compared to other groups (≤ 1 year and 1-≤ 5 years) (p=0.02, p=0.01, p=0.001, p=0.01 and p=0.05 respectively). Further, significant increase in the levels of NO, MDA and decreased activities of SOD, CAT were found in treated patients compared to untreated patients (p<0.05) denoting that additional oxidative stress induced by AEDs which results in seizure recurrence and drug intractability. CONCLUSION: Our study demonstrated that GGE patients have additional oxidative stress due to AEDs and decreased antioxidant enzyme activities causing an imbalance between oxidant and antioxidant status, which might contribute to the pathogenesis of GGE.

Association of serum trace elements and minerals with genetic generalized epilepsy and idiopathic intractable epilepsy.

Certain minerals and trace elements are essential for the development of healthy nervous system. Altered serum levels of these elements may lead to the development of various diseases including epilepsy. The present study was designed to evaluate the association of serum calcium, magnesium, zinc and copper in the development of genetic generalized epilepsy [GGE; erstwhile known as idiopathic generalized epilepsy (IGE)] as well as idiopathic intractable epilepsy (IIE), in which seizures persist despite treatment with at least two or three antiepileptic drugs tolerated at reasonable dosage. 200 GGE patients and equal number of healthy controls were recruited for study with their written informed consent. The patients were further divided into responders and non-responders based on their response to antiepileptic drugs. Copper and zinc levels were assayed by atomic absorption spectrophotometer whereas calcium and magnesium were analyzed by Human Star 600 fully automated biochemistry analyzer. The patients with GGE had significant low levels of calcium, magnesium and zinc (1.85 ± 0.33, 0.69 ± 0.13 mmol/L and 11.33 ± 3.32 µmol/L respectively) and the corresponding values for controls were 2.27 ± 0.22, 0.89 ± 0.15, 12.71 ± 3.24 (p < 0.05). Significant high levels of copper were found in patients as compared to controls (26.69 ± 8.79 µmol/L; 16.64 ± 3.64) (p < 0.05). Significantly decreased levels of zinc were noted in non-responders (10.38 ± 2.99) compared to responders (12.62 ± 3.30) (p < 0.05). No significant difference was observed in serum calcium, magnesium and copper levels between responders and non-responders. In conclusion, low levels of calcium, magnesium, zinc and high levels of copper were found to be associated with GGE. Further, the patients with IIE were also found to have low levels of zinc.

Association of GABRA6 1519 T>C (rs3219151) and Synapsin II (rs37733634) gene polymorphisms with the development of idiopathic generalized epilepsy.

The idiopathic generalized epilepsy (IGE) is a neurological disorder which accounts for approximately 30% of all epilepsy cases. Patients identified with IGE syndromes have pharmacoresponsive epilepsies without abnormal neurological symptoms, structural brain lesions and are of unknown origin. A genetic etiology to IGEs has been proposed. Gamma amino butyric acid (GABA), a major inhibitory neurotransmitter acts by binding to transmembrane GABAA and GABAB receptors of both pre- and postsynaptic neurons. Synapsin II (SynII), a neuron specific phosphoprotein plays a major role in synaptogenesis and neurotransmitter release. The present study was carried out with an aim to evaluate the association of GABRA6 (rs3219151) T>C and Syn II (rs37733634) A>G gene polymorphisms with IGE. Molecular analysis revealed that the frequency of 'CC' genotype and 'C'allele of GABRA6 (rs3219151) T>C gene polymorphism was significantly higher in IGE patients compared to healthy controls [CC vs. TT, χ2=26; p<0.001; Odds ratio=3.6 (95% CI; 2.1-5.9); C vs T, χ2=24.7; p<0.001; Odds ratio=1.78 (95% CI; 1.4-2.2)]. The frequency of 'GG' genotype and 'G' allele of the intronic polymorphism A>G in Syn II gene was also found to be significantly associated with the disease when compared to controls [GG vs AA, χ2=64.52; p<0.001; Odds ratio=7.37 (95% CI; 4.4-12.3); G vs. A, χ2=65.78; p<0.001; Odds ratio=2.57 (95% CI; 2.0-3.2)]. The generalized multifactor dimensionality reduction method was employed to detect gene-gene interactions. The gene-gene interaction at two loci involving GABRA6 and Syn II revealed a significant association [χ2=36.6, p<0.001, Odds ratio=3.17 (95% CI; 2.2-4.6)] with IGE. Therefore, the present study clearly indicates that both GABRA6 (rs3219151) T>C and Syn II (rs37733634) A>G polymorphisms are important risk factors for the development of IGE in the South Indian population from Andhra Pradesh. The gene-gene interaction studies demonstrated significant interactive effects of these two loci in the development of the disease.

Significance of MDR1 gene polymorphism C3435T in predicting drug response in epilepsy.

Antiepileptic drug (AED) treatment in epilepsy is often compromised by the unpredictability of efficacy and inter-individual variability among patients, which at least in part is the result of genetic variation. The idea to determine an individual's response to a prescribed medicine came into inception around 29 years ago. Pharmacogenetics is used to predict the drug response and efficacy, as well as potential adverse effects. We investigated the functional significance of the C3435T polymorphism of the MDR1 gene in a South Indian population. The patients were divided into responders and non-responders based on their clinical outcome and AED response. The risk of drug resistance was significantly higher in patients bearing TT genotype in comparison to carriers of the homozygous CC genotype [TT vs. CC, χ(2)=12.52; p=0.001, Odds ratio=2.34 (95% CI: 1.942-11.32)]. We suggest that the influence of the C3435T polymorphism in predicting the drug-resistance in epilepsy, might be significant and further investigations focusing on carbamazepine and phenytoin, in various ethnic populations are necessary to clarify the effect of C3435T polymorphism on the multidrug resistance in epilepsy patients.

Genetics of idiopathic generalized epilepsy: an overview.

Idiopathic generalized epilepsy (IGE) is a common type of epilepsy. Strong support for a genetic role in IGE comes from twin and family studies. Several subtypes of IGE have been reported but families often have members affected with different subtypes. Major advances have been made in the understanding of genetic basis of monogenic inherited epilepsies. However, most IGEs are complex genetic diseases and some susceptible IGE genes are shared across subtypes that determine subtypes in specific combinations. The high throughput technologies like deoxyribonucleic acid microarrays and sequencing technologies have the potential to identify causative genes or loci in non-familial cases.

Biliary atresia with a "cyst at porta": management and outcome as per the cholangiographic anatomy.

The purpose of this study is to classify biliary atresia (BA) with a "cyst at porta" according to the cholangiographic anatomy and to define management strategy and outcome in each group. A cyst at porta was identified in 13 of 58 babies (22.4%) with BA at first presentation. The cholangiographic anatomy was classified as; Group A (n = 7), type III BA with extrahepatic cyst; Group B (n = 2), type I or II BA with extrahepatic biliary cyst; and Group C (n = 4), type I or II BA with both extrahepatic and intrahepatic biliary cysts. The remaining 45 patients were comprised of type III BA without a cyst. A Kasai's portoenterostomy (PE) was performed for all Group A patients. Groups B and C were treated by hepaticojejunostomy (n = 5) or portoenterostomy (n = 1). All 45 patients with type III BA without a cyst were treated by a Kasai's PE. The median age at surgery was 92 days (ranges 28-342 days). There were three early post-operative deaths, all in patients with type III BA without cyst. Overall 18/55 (32.7%) patients achieved a jaundice free state. In Group A, 5/7 (71.4%) patients had bile flow, 2/7 (28.6%) are anicteric and 2/7(28.6%) had 1-2 episodes of post-operative cholangitis. In Group B, both patients are anicteric and none had post-operative cholangitis. In Group C, all four babies had bile flow but, significant morbidity because of recurrent severe cholangitis. Only one patient reached a jaundice free state. Of the remaining 42 patients with type III BA without a cyst, 27 (64.3%) had bile flow, 13 (31%) became jaundice free and 14 (33.3%) have had 1-2 episodes of post-operative cholangitis. In conclusion, thirteen of 58 (22.4%) babies with BA had a "cyst at porta" at first presentation in this series. The outcome was most satisfactory in type I BA without intrahepatic cystic dilatation (Group B) in terms of achieving a jaundice free state and freedom from recurrent cholangitis. However, intrahepatic biliary cysts (Group C) were associated with recurrent severe cholangitis and a poor eventual outcome despite a good initial bile flow. The outcome in type III BA with extrahepatic cyst was comparable to type III BA without cyst.