Screening of the A11084G Polymorphism and Scanning of a Mitochondrial Genome SNP in Korean Migraineurs

A Comprehensive Review on the Role of Genetic Factors in the Pathogenesis of Migraine

Migraine is a common neurovascular condition. This disorder has a complex genetic background. Several single-nucleotide polymorphisms (SNPs) or mutations within genes regulating glutamatergic neurotransmission, cortical excitability, ion channels, and solute carriers have been associated with polygenic and monogenic forms of migraine. SNPs within ACE, DBH, TRPM8, COMT, GABRQ, CALCA, TRPV1, and other genes have been reported to affect the risk of migraine or the associated clinical parameters. The distribution of some HLA alleles within the HLA-DRB1, HLA-DR2, HLA-B, and HLA-C regions have also been found to differ between migraineurs and healthy subjects. In addition, certain mitochondrial DNA changes and polymorphisms in this region have been shown to increase the risk of migraine. A few functional studies have investigated the molecular mechanisms contributing to these genetic factors in the development of migraine. Here we review studies evaluating the role of genetic polymorphisms and mRNA/miRNA dysregulation in migraine.

No evidence of association between common European mitochondrial DNA variants in Alzheimer, Parkinson, and migraine in the Spanish population

Certain mitochondrial DNA (mtDNA) variants and haplogroups have been found to be associated with neurological disorders. Several studies have suggested that mtDNA variation could have an etiologic role in these disorders by affecting the ATP production on high-energy demanding organs, such as the brain. We have analyzed 15 mtDNA SNPs (mtSNPs) in five cohorts of cases presenting Alzheimer disease (AD), Parkinson disease (PD), and migraine, and in controls, to evaluate the role mtDNA variation in disease risk. Association tests were undertaken both for mtSNPs and mitochondrial haplogroups. No significant association was detected for any mtSNP or haplogroup in AD and PD cohorts. Two mtSNPs were associated with one migraine cohort after correcting for multiple tests, namely, T4216C and G13708A and haplogroup J (FDR q-value = 0.02; Santiago's cohort). However, this association was not confirmed in a second replication migraine series. A review of the literature reveals the existence of inconsistent findings and methodological shortcomings affecting a large proportion of mtDNA association studies on AD, PD, and migraine. A detailed inspection of the literature highlights the need for performing more rigorous methodological and statistical standards in mtDNA genetic association studies aimed to avoid false positive results of association between mtDNA variants and neurological diseases.

Current research status, databases and application of single nucleotide polymorphism

Single Nucleotide Polymorphisms (SNPs) are the most frequent form of DNA variation in the genome. SNPs are genetic markers which are bi-allelic in nature and grow at a very fast rate. Current genomic databases contain information on several million SNPs. More than 6 million SNPs have been identified and the information is publicly available through the efforts of the SNP Consortium and others data bases. The NCBI plays a major role in facillating the identification and cataloging of SNPs through creation and maintenance of the public SNP database (dbSNP) by the biomedical community worldwide and stimulate many areas of biological research including the identification of the genetic components of disease. In this review article, we are compiling the existing SNP databases, research status and their application.

Frovatriptan is Effective and Well Tolerated in Korean Migraineurs: A Double-Blind, Randomized, Placebo-Controlled Trial

Background and Purpose

Frovatriptan is a selective 5-HT_1B/1D agonist with a long duration of action and a low incidence of side effects. Although several placebo-controlled trials have documented the clinical efficacy and safety of frovatriptan in adults with migraine, this drug has not previously been studied in Asian including Korean patients.

Methods

In this double-blind multicenter trial, 229 patients with migraine were randomized to receive frovatriptan 2.5 mg or placebo upon the occurrence of a moderate-to-severe migraine. The primary outcome was the 2-hour headache response rate.

Results

Frovatriptan significantly increased the 2-hour headache response rate compared with placebo (52.9% vs. 34.0%, p=0.004). The headache response rates at 4, 6, and 12 hours were significantly higher in the frovatriptan group than in the placebo group, as was the pain-free rate at 2 hours (19.0% vs. 5.7%, p=0.004), 4 hours (40.7% vs. 23.0%, p=0.006), and 6 hours (56.1% vs. 34.0%, p=0.002). The median time to a headache response was significantly shorter in the frovatriptan group than in the placebo group (2.00 hours vs. 3.50 hours, p<0.001). The use of rescue medications was more common in the placebo group (p=0.005). Chest tightness associated with triptan was infrequent (2.5%), mild, and transient.

Conclusions

These results demonstrate that 2.5-mg frovatriptan is effective and well tolerated in Korean migraineurs for acute treatment of migraine attacks.