Familial typical migraine: significant linkage and localization of a gene to Xq24-28

In a previous study we found evidence for an X-linked genetic component for familial typical migraine in two large Australian white pedigrees, designa ted MM and MFI I. Significant excess allele sharing was indicated by nonpar ametric linkage (NPL) analysis using GENE-HUNTER (P = 0.031 and P = 0.012, respectively), with a combined analysis of the two pedigrees showing furthe r increased evidence for linkage, producing a maximum NPL score of 2.87 (P = 0.011) at DXS 1123 an Xq27. The present study was aimed at refining the l ocalization of the migraine X-chromosomal component by typing additional ma rkers, performing haplotype analysis and applying a more powerful technique in the analysis of linkage data from these two pedigrees. Results from the haplotype analyses, coupled with linkage analyses that produced a peak GEN EHUNTER-PLUS LOD* score of 2.388 (P = 0.0005), provide compelling evidence for the presence of a migraine susceptibility locus on chromosome Xq24-28.