Migraine With Or Without Aura, Susceptibility To, 11

For a phenotypic description and discussion of genetic heterogeneity of migraine headaches, see MGR1 (157300).

Mapping

Since migraine is a syndrome instead of a clearly differentiated disease, Anttila et al. (2006) hypothesized that individual clinical components of migraine (i.e., traits such as pulsating pain and photophobia, among others) might represent reflections of specific rather than shared loci and thus independently contribute to susceptibility to migraine. To test this hypothesis, they used individual traits and trait groups of the International Headache Society (IHS) criteria as phenotypes for genomewide linkage analysis in the same dataset of 50 Finnish families used to establish the MGR1 locus (Wessman et al., 2002). In addition to confirming the MGR1 locus on 4q24, Anttila et al. (2006) detected linkage between marker D18S877 on chromosome 18q12.1 and the full IHS criteria, with a 2-point hlod of 3.29. With this marker, individual traits showed suggestive evidence of linkage, with vascular criteria (3.14), attack length (3.00), and aggravation by physical exercise (2.77) showing the highest lod scores. The authors fine-mapped this locus with 5 additional markers, providing a map interval of 3.2 cM.