Clinical Significance Of Mitochondrial Genome Sequencing In Patients With Refractory Epilepsy

Objective To investigate the relationship between patients with refractory epilepsy and mitochondrial genome, explore the unknown mtDNA mutations or phenotype. Methods From January 2013 to December 2014, we selected 54 inpatients with refractory epilepsy at the Department of Neurology, Xijing Hospital, Fourth Military Medical University, China. The mitochondrial genome of these patients was examed by Polymerase chain reaction（PCR） and Sanger sequencing and the result was compared with normal mitochondrial genome（NC₀12920.1） in NCBI database. Results A total of 34 males and 20 females were recruited. We found 33 Single Nucleotide Polymorphisms（SNP）（2 SNPs on gene MT-RNR1, 2 SNPs on gene MT-RNR2, 6 SNPs in tRNA coding region,21 SNPs in polypeptide coding region and 2 SNPs in DLoop region） in these patients. Compared with allele frequency of Han Chinese in Beijing in NCBI database, it reviewed that the frequency of m.13708G>A（χ2=13.198, P<0.01） and m.14668C>T（χ2=28.614, P<0.01） are more frequently. Three causative mutations were found in these patients. m.636A>G and m.7445A>C are associated with Maternally Inherited DEAFness or Aminoglycoside-induced DEAFness（DEFA）, mt3243A>G is associated with Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like Episodes（MELAS） and Chronic Progressive External Ophthalmoplegia（CPEO） et al. In addition, we found 4 novel mutations. m.15018 T>A, m.15066 T>A are on the mt-cytb, mt14207G>C and mt14288 C>A are on the MT-CO1. Conclusions The examitation of mitochondrial genome in patients with refractory epilepsy could provide clues for the etiological diagnosis of patients with intractable epilepsy.