Genetic Polymorphisms Of Common Primary Headaches

Background:Primary headaches,including cluster headache(CH),migraine,and tension-type headache(TTH),are the most common clinical symptom and have no clear etiology or pathogenic mechanism.Genetic and environmental factors are thought to potentially contribute to these primary headaches.Cluster headache is characterized by a periodic onset and induced by alcohol consumption during the cluster period of time;thus,abnormal biological clock function in hypothalamus was considered as its pathophysiology.Single nucleotide polymorphisms(SNPs)of Hypocretin receptor 2(HCRTR2),Circadian locomotor output cycles kaput(CLOCK),and Alcohol dehydrogenase 4(ADH4)have been shown to associate with cluster headache,but no similar studies have been conducted in China.Some studies have shown that estrogen was involved in development of migraine and that the Estrogen receptor(ESR)polymorphism associated with the onset of migraine.To date,the results of association between ESR1 polymorphisms and migraine are inconsistent in China and abroad.Similar causes of TTH and migraine have led to speculation that they may have the same pathogenesis,but there is no study of association between ESR1 polymorphism and TTH in China.Methods:Venous blood samples were withdrawn from 112 cluster headache patients vs.192 age and gender-matched healthy controls and 328 migraine patients and 102 TTH vs.297 healthy controls.Genomic DNA was extracted from these cluster headache cases and controls for genotyping of HCRTR2(rs10498801,rs2653342,rs2653349,rs3122156,rs3800539,and rs9357855),ADH4(rs1126671 and rs1800759),and CLOCK(rs1801260)using the Sequenom MALDI-TOF mass spectrometry iPLEX platform.The genotypic and allelic frequencies and haplotypes of these three gene SNPs were statistically analyzed and compared between the case and control groups for association with cluster headaches.Genomic DNA was extracted from migraine and TTH patients vs.controls for genotyping ESR1(rs2234693)using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP).The frequencies and distributions of genotypes were statistically compared between the case and control groups to identify associations with migraine and TTH.Results:①The CH group:The frequency of the HCRTR2 SNP rs3800539 GA genotype was significantly higher in cases than in controls(48.2%vs.37.0%).The GA genotypes was associated with a higher CH risk(OR=1.483,95%CI:0.564-3.387,P=0.038),however,after Bonferroni correction,the association lost statistical significance.Subgroup analysis,also supported the above conclusion.Haplotype analysis of the HCRTR2 SNPs showed that among eight haplotypes,only H1 Haplotype was linked to a reduced CH risk(44.7%vs.53.1%,OR=0.689,95%CI =0.491～0.966,P=0.030),but the male CH group did not get a similar conclusion.Multiple logistic regression analysis showed that there was no significant difference in CH group as a whole,but subgroup analysis showed that HCRTR2 rs3800539 could significantly increase the CH risk in male patients for the GA+AA genotype carriers compared with subjects with GG genotype(OR = 1.525,95%CI:1.030-2.257,P = 0.035).No significant association of other HCRTR2 SNPs,ADH4 SNPs,CLOCK SNPs with CH was statistically detected in the present study.②The Migraine group:The genotype and allele frequency distribution of ESR1 gene rs2234693 SNPs were no significant difference between migraine group and control group(P>0.05).CT genotype,CC genotype were not correlated with migraine(OR = 1.197,95%Cl:0.851-1.684,P =0.301;OR = 1.418,95%CI:0.883-2.277,P = 0.148).Compared with the T allele,the C allele did not increase the risk of migraine(OR = 1.208,95%Cl:0.959-1.522,P=0.109).No association was found between ESR1 gene rs2234693 polymorphism and MO and MRM.③TTH group:There was no significant difference in genotype and allele frequency distribution of ESR1 gene rs2234693 SNPs between TTH group and control group(P>0.05).CT genotype,CC genotype and TTH incidence were not correlated(OR = 1.200,95%CI:0.741-1.945,P = 0.458;OR = 1.029,95%CI:0.503-2.105,P=0.937).Compared with T allele,C allele did not increase the risk of TTH(OR = 1.065,95%CI:0.764-1.486,P = 0.709).Conclusions:This study was the first to study the polymorphism of CH and HCRTR2,ADH4 and CLOCK genes in Chinese Han population.The results showed that the polymorphism of HCRTR2(rs10498801,rs2653342,rs2653349,rs3122156,rs9357855,and rs3800539),ADH4(rs1126671 and rs1800759),and CLOCK(rs1801260)SNPs were not correlated with the occurrence of CH in Chinese Han population.However,haplotype analysis showed that the H1 Haplotype may associate with reduced CH risk.The multiple logistic regression analysis showed that HCRTR2 rs3800539 the GA+AA genotype could significantly increase the CH risk in male patients compared with subjects with GG genotype.Furthermore,there was no association between migraine and ESR1 rs2234693 polymorphism.ESR1(rs2234693)polymorphism was neither correlated with MO nor MRM.In addition,there was no association between ESR1(rs2234693)polymorphism and TTH.