Abstract

Clinical and genetic heterogeneity as well as the influence of environmental factors have hampered the identification of the genetic factors, which are involved in episodic diseases such as migraine and episodic ataxia. Although not sufficiently reliable, family studies and twin studies suggest that migraine likely is influenced by hereditary susceptibility. Migraine with aura(MWA) seems to be largely determi- ned by genetic factors, whereas migraine without aura(MOA) caused by a combination of both genetic and environmental factors, hence migraine is supposed to be a multifactorial disorder. Recently, different types of mutations in the brain specific P/Q type calcium channel 1A subunit gene(CACNA1A) on chromosome 19p13 were shown to be involved in familial hemiplegic migraine(FHM), episodic ataxia type 2(EA-2), and spinocerebellar ataxia type 6(SCA-6). A gain of function variant of the calcium channel subunit would probably influence presynaptic neurotransmitter release, possibly of excitatory aminoacid or inhibitory serotonergic systems, leading to postsynaptic neuronal excitability. The impor- tance of these discoveries is now being extended to a growing list of membrane excitability disorders of the nervous system. And identification of candidate genes for migraine is expected in the future. Korean Journal of Headache 1(1):32-38, 2000