For a single gene test, it was demonstrated that 3435C>T in the ABCB1 gene had a significant effect on epilepsy treatment responses, but polymorphisms in the NR1I2 gene did not.
The ABCB1 T-129C, C1236T, G2677T/A and C3435T polymorphisms were genotyped in 210 Japanese epileptics who had been prescribed AEDs, including CBZ, for longer than 2 years.
One hundred and eight patients with drug-responsive epilepsy, 63 patients with drug-resistant epilepsy, and 219 control migraine subjects were studied, but the analysis for C3435T allele showed no significant association between the CC genotype and the multidrug-resistant epilepsy.
The ABCB1 3435C-->T single-nucleotide polymorphism (SNP) or a three-SNP haplotype containing 3435C-->T has been implicated in multidrug resistance in epilepsy in three retrospective case-control studies, but a further three have failed to replicate the association.