Year: 1995
Type: editorial
Abstract: Association study in migrainePardo et al.'s report in this issue of Cephalalgia adds to the growing research on the genetics of migraine.Different approaches are possible for elucidating the hereditary component in migraine.Linkage analysis in families with familial hemoplegic migraine (FHM), a rare subtype of migraine with aura, have provided evidence for a locus on chromosome 19 (1).A recent study suggests the involvement of the chromosome 19 locus also in "normal" migraine (2) However, in some of the FHM families, evidence against linkage to 19 was shown, indicating non-allelic genetic heterogeneity (3-4).It is, therefore, quite likely that several genes are involved in "normal" migraine as well.Association studies may provide clues for detection of a weak association between markers and a disease (5).Pardo et al. conducted a population-based association study, comparing migraine patients with healthy volunteers for 11 markers localized in or near candidate loci.They observed association for two markers, the Group Component (GC: phenotype 1F-1F) and Esterase D (ED: phenotype 2-2).Their findings should be viewed with caution, however, because: (i) the high odds ratio for the GC marker is possibly due to the low number of subjects in the control group with the 1F-1F phenotype.This problem might have been circumvented had family members been selected as controls rather than healthy independent individuals; (ii) association would have been more reliable if the two markers were in the candidate region of interest rather than near this region; and (iii) if the F1-F1 phenotype (GC) or 2-2 phenotype (ED) is to be of relevance in migraine, the contribution of these phenotypes would be extremely low (8% respectively 10%).Although the findings of Pardo et al. are interesting, one cannot determine, based on association analysis alone, how important these loci are for migraine.There could be major disease genes at other loci, distinct from the markers (as Pardo et al. suggest), or there could be genes that merely increase susceptibility slightly, possibly located at the marker loci themselves.Therefore, linkage analysis in migraine families has to be performed in order to clarify the association found and the biological mechanism causing the association.
Source: Cephalalgia
Authors: G M Terwindt, M D Ferrari
Language: Spanish
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2414874754