THE GENETICS OF MIGRAINE

Several historical reports focusing on the heredity of migraine, as we ll as recent studies on its epidemiology and molecular biology, have r evealed evidence for a decisive role of genetic factors in the aetiopa thogenesis of familial migraine. Indeed, family studies, segregation a nalyses and twin studies have shown that genetic factors play an impor tant role in disposition towards migraine but could not explain the en tire aetiopathogenesis. The influence of extragenetic factors, however , remains mostly unknown. Recent linkage analyses have provided eviden ce for genetic heterogeneity. A locus for Familial Hemiplegic Migraine (FHM), the only known type of migraine that follows autosomal-dominan t transmission, has been linked to chromosome 19p13 but genetic hetero geneity has also been shown, i.e. different types of migraine could be excluded from this locus. Further investigations should concentrate o n identifying the FHM gene on chromosome 19p13, on linkage analyses wi th markers for different susceptibility genes, and on genomic analyses of highly informative pedigrees. This would lead to further clues to the pathogenesis underlying migraine and, thus, to therapeutic develop ments.