title: A genotype-phenotype analysis of the 8q22.1 variant in migraine with aura.
abstract: OBJECTIVE
  Although the genetics of familial hemiplegic migraine are being unraveled, this is not the case for the prevalent types of migraine. However, a recent genome wide association study (GWAS) reported an association of the single nucleotide polymorphism (SNP) rs1835740 and migraine. The aim of this study is to evaluate the association of clinical characteristics in migraine with aura (MA) with the newly discovered minor allele A of rs1835740 at 8q22.1.
  
  
  METHODS
  Participants were recruited from the Danish Headache Center and from specialist practices during the periods 1999-2002 and 2005-2006, and diagnosed according to the International Classification of Headache Disorders (ICHD-II) using a validated physician-conducted semi-structured interview. A large number of clinical characteristics were systematically determined. Caucasians of Danish ancestry diagnosed with MA and successfully genotyped for the SNP rs1835740 were included. Patients with hemiplegic migraine were excluded. Blood samples were collected for extraction of genomic DNA and genotyped for the common susceptibility variant rs1835740.
  
  
  RESULTS
  Six hundred and ninety one successfully genotyped MA patients with substantial description of their clinical characteristics were included. Two hundred and fifty one were heterozygous and 40 were homozygote for the variant marker. Carriers of the rs1835740 variant showed a non-significant tendency towards having a higher frequency of aura symptoms and a non-significant tendency towards milder migraine headache characteristics and fewer accompanying symptoms. These tendencies were not increased in homozygote carriers.
  
  
  CONCLUSIONS
  None of the clinical characteristics of MA were significantly influenced by the common susceptibility variant on 8q22.1.
authors: The Danish Headache Center, Department of Neurology, Glostrup Hospital, University of Copenhagen, Denmark.
authors: A-L
authors: AL
authors: Esserlind
authors: M
authors: M
authors: Kirchmann
authors: A W
authors: AW
authors: Hauge
authors: H
authors: H
authors: Le
authors: J
authors: J
authors: Olesen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002268:Carboxypeptidases / Q000235:genetics; D002648:Child; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D003718:Denmark; D004198:Disease Susceptibility; D005260:Female; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008297:Male; D008354:Mannitol Dehydrogenases / Q000235:genetics; D008875:Middle Aged; D020325:Migraine with Aura / Q000235:genetics* / Q000503:physiopathology*; D010147:Pain Measurement; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D008354:Mannitol Dehydrogenases; C116789:mannitol 2-dehydrogenase (NADP); D002268:Carboxypeptidases