Familial hemiplegic migraine and episodic ataxia type-2 are caused by mutations in the Ca2+ channel gene CACNL1A4.
Ophoff RA,
Terwindt GM,
Vergouwe MN,
van Eijk R,
Oefner PJ,
Hoffman SM,
Lamerdin JE,
Mohrenweiser HW,
Bulman DE,
Ferrari M,
Haan J,
Lindhout D,
van Ommen GJ,
Hofker MH,
Ferrari MD,
Frants RR.
MGC-Department of Human Genetics, Sylvius Laboratory, Leiden University, The Netherlands.
Genes for familial hemiplegic migraine (FHM) and episodic ataxia type-2 (EA-2) have been mapped to chromosome 19p13. We characterized a brain-specific P/Q-type Ca2+ channel alpha1-subunit gene, CACNL1A4, covering 300 kb with 47 exons. Sequencing of all exons and their surroundings revealed polymorphic variations, including a (CA)n-repeat (D19S1150), a (CAG)n-repeat in the 3'-UTR, and different types of deleterious mutations in FHM and EA-2. In FHM, we found four different missense mutations in conserved functional domains. One mutation has occurred on two different haplotypes in unrelated FHM families. In EA-2, we found two mutations disrupting the reading frame. Thus, FHM and EA-2 can be considered as allelic channelopathies. A similar etiology may be involved in common types of migraine.
PMID: 8898206 [PubMed - indexed for MEDLINE]