Association Of SCN1B Single Nucleotide Polymorphism With Epilepsy

Objective:To study the single nucleotide polymorphisms (SNP) in 3 sites allele(T189M, R85H, C121W) of voltage-gated sodium channel beta 1 subunit gene(SCN1B) in Chinese idiopathic epilepsy patients and explore whether SCN1B mutation is the reason for epilepsy.Method:342 blood samples of refractory(84 cases),non-refractory(108 cases) epilepsy patients and healthy people(150cases) were collected. Genomic DNA of leucocyte were extracted. SNPs of three sites allele(T189M-11606C/T,R85H-5881G/A and C121W-6062C/G) of SCN1B were tested by allele-specific primer-polymerase chain reaction(ASP-PCR).Data were analyzed by SAS8.1 statistical software.Results :Epilepsy group and healthy group had significantly statistical difference in composition of 3 sites allele on single site genotype (χ2=11.19, 11.14 and 6.50, all P<0.05). There was no statistical significance between refractory and non-refractory epilepsy group. On gene combination, in 27 different combinations of polymorphism, mutation frequency in 3 sites (CT+AG+CG) was highest in epilepsy group(18.40%).The next was 1 site in CT+GG+CC(16.80%).In healthy group, frequency of non-variant in CC+GG+CC was highest(16.67%),and the next was 2 sites in CT+AG+CC(13.73%).35 cases in epilepsy group(28.80%) had 3 sites mutation compared with 10 cases in healthy group(9.71%),and their difference had statistical significance(p<0.05);18 cases in refractory epilepsy group(30.51%) had 3 sites mutation compared with 21 cases in non-refractory epilepsy group(28.77%),and the difference had no statistical significance(p<0.05).50 cases in epilepsy group(40.00%) had 2 sites mutation compared with 41 cases in healthy group(40.20%),and there was no statistical significance(p>0.05) between them;25 cases in refractory epilepsy group(42.37%) had 2 sites mutation compared with 21 cases in non-refractory epilepsy group(28.71%),and their difference had no statistical significance(p>0.05).There was a difference of genotype distribution between groups with typical and untypical epilepsy EEG(P<0.001).Conclusion:The results indicate that mutation,especially multisite mutation of SCN1B is relatively liable to cause epilepsy in human and It is easier for the patients to present EEG characterisitic of typical epilapsy .Gene distribution and combination of three sites allele of SCN1B in refractory epilepsy is close to that in non-refractory epilepsy.