The genetics of migraine without aura and migraine with aura.

Studies of twins, spouses and familial aggregation strongly suggest that migraine without aura (MO) and migraine with aura (MA) are genetically determined. The mode of inheritance is most likely multifactorial in both MO and MA. However, autosomal dominant inheritance with reduced penetrance cannot be excluded in either MO or MA. At present the only evidence for genetic heterogeneity of MA is familial hemiplegic migraine with slowly progressive ataxia. This phenomenon can also be explained by linkage of different genes. All existing studies have been characterized by one or more of the following methodologic shortcomings: selection of probands from clinic populations, information obtained by questionnaire, family history obtained through probands, insufficient description of the attacks, lack of distinction between MO and MA. Useful strategies for future studies of migraine genetics are discussed.