[Genetic aspects of migraine].
METHODS
On the basis of studies identified by Medline and PubMed searches, this review focuses on the genetics of migraine.


RESULTS
Compared to the general population, first-degree relatives of probands with migraine without aura (MO) have a two-fold risk of MO, whereas first-degree relatives of probands with migraine with aura (MA) have a four-fold increased risk of MA. Population-based family and twin studies have shown that migraines with or without aura have a multifactorial inheritance. In patients with familial hemiplegic migraine, a rare variant, a mutated gene encoding a subunit of a brain-specific calcium channel in cell membranes has been found (CACNA1A). This gene may be of importance in the common forms of migraine in a few families and, at least in part, migraine may be a genetically determined channelopathy. However, migraine has also been linked to other genes with other functions, which makes the picture less clear.


CONCLUSIONS
It is to be hoped that in the next few years much more will be known about the molecular genetic mechanisms of migraines with and without aura. No gene is as yet defined.
Avdeling for nevrologi og klinisk nevrofysiologi, St. Olavs Hospital, 7006 Trondheim. knut.hagen@medisin.ntnu.no
Knut
K
Hagen
D020022:Genetic Predisposition to Disease; D006801:Humans; D008881:Migraine Disorders / Q000235:genetics*; D012307:Risk Factors