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Biomedical subjects

G M Terwindt

Publications and source records attributed to G M Terwindt.

At least 37 records · Page 2Linked to original sources

[Channelopathies: a genetic explanation of migraine and other paroxysmal neurologic disorders].

There is increasing evidence of involvement of genes coding for ion channels in the pathogenesis of paroxysmal neurological disorders. Recently for instance, mutations in the calcium channel gene on chromosome 19 were identified in migraine, ataxia, and epilepsy. With the current research into inherited 'channelopathies' a new approach has been established. A better understanding of the pathophysiology of paroxysmal neurological disorders may lead to new therapeutic strategies.

Epilepsy↗

Clinical and genetic analysis of a large Dutch family with autosomal dominant vascular retinopathy, migraine and Raynaud's phenomenon.

We describe an extended Dutch family with a new hereditary disorder: autosomal dominant vascular retinopathy, migraine and Raynaud's phenomenon. Information was obtained on 289 family members (151 males, 138 females), of whom 198 were personally interviewed. Retinopathy was found in 20 (6.9%) of the family members, migraine in 65 (22.5%) and Raynaud's phenomenon in 50 (17.3%). A combination of all three symptoms was found in 11 subjects. In a genetic linkage analysis we firstly excluded several candidate loci. Subsequently, 75% of the autosomal genome was excluded in a genome-wide search. The following conclusions were drawn. First, genetic factors are involved in Raynaud's phenomenon. Secondly, the genetic linkage of migraine with vascular retinopathy and Raynaud's phenomenon supports a vascular aetiology of this disorder. Finding the gene for this family may help to elucidate the genetic background of migraine and of vascular disorders in general.

Adolescent↗

Variable clinical expression of mutations in the P/Q-type calcium channel gene in familial hemiplegic migraine. Dutch Migraine Genetics Research Group.

Familial hemiplegic migraine (FHM) is an autosomal dominant subtype of migraine with aura, with half of the families being assigned to chromosome 19p13. We identified missense mutations in a brain-specific calcium channel alpha1A-subunit (CACNA1A) gene on 19p13 segregating with FHM and truncating mutations in families with episodic ataxia type 2 (EA-2). Expansions of an intragenic CAG repeat have been shown in autosomal dominant cerebellar ataxia (SCA6). Hence, FHM, EA-2, and SCA6 are allelic ion channel disorders. We analyzed the phenotype-genotype relation in three unrelated FHM families with the calcium channel alpha1A-subunit gene mutations I1811L (two families) and V714A (one family). We found mutations in all but three patients with FHM (i.e., three phenocopies). In addition, the I1811L mutation occurred in two patients with "nonhemiplegic" migraine and in one subject without migraine. Cerebellar ataxia was found in both families with the I1811L mutation but not in the family with the V714A mutation. We failed to find expansions of the intragenic CAG repeat in FHM patients with cerebellar ataxia. We conclude that the I1811L mutation causes both FHM and cerebellar ataxia independent of the number of CAG repeats. The I1811L mutation may also occur in "normal" migraine patients, supporting the hypothesis that FHM is part of the migraine spectrum.

Adolescent↗

Genetics and pathology of voltage-gated Ca2+ channels.

Neurotransmitter release, neuronal excitation, and a whole variety of other neuronal functions are controlled by the intra/extra cellular Ca2+ gradient. The major pathway for entry of Ca2+ into the excitable cells is mediated by voltage-gated Ca2+ channels. Several functional subclasses of voltage-dependent Ca2+ channels have been identified, based on their pharmacological, biophysical properties, and molecular cloning. Recently, three human diseases (familial hemiplegic migraine, episodic ataxia type 2, and spinocerebellar ataxia 6) were added to the growing list of ion-channel disorders, all caused by different mutations in the P/Q-type Ca2+ channel alpha 1 subunit. Molecular analysis of the Ca2+ channelopathies will provide new insights into the role, function and pathology of these voltage-gated Ca2+ channels.

Animals↗

Genetics of migraine.

Although family studies and twin studies are not sufficiently reliable to establish this theory with certainty, migraine likely is influenced by hereditary susceptibility. The association of migraine with a large number of hereditary diseases opens the possibility to choose candidate chromosomes for linkage studies. A rare subtype of migraine, familial hemiplegic migraine, is linked to chromosome 19p and at least one other locus. The chromosome 19p also seems to be involved in "normal" migraine, although conflicting results have been reported.

Humans↗

Wolff Award 1997. Involvement of a Ca2+ channel gene in familial hemiplegic migraine and migraine with and without aura. Dutch Migraine Genetics Research Group.

A gene for familial hemiplegic migraine, a subtype of migraine with aura, was assigned to chromosome 19p13. In this region, we identified a brain-specific P/Q-type calcium-channel alpha 1A-subunit gene, CACNA 1A, with 47 exons covering 300 kb. Sequencing of all exons and their flanking surroundings revealed polymorphic variations, including a (CA)n-repeat and a (CAG)n-repeat in the 3' untranslated region. In patients with familial hemiplegic migraine, we found four different missense mutations in conserved functional domains. One of the mutations has occurred on two different haplotypes in unrelated familial hemiplegic migraine families. Moreover, in episodic ataxia type 2, we found two mutations disrupting the reading frame. Thus, familial hemiplegic migraine and episodic ataxia type 2 can be considered as allelic channelopathies. Involvement of this familial hemiplegic migraine locus in migraine with and without aura was demonstrated by sib-pair analysis. We showed an increase of shared marker alleles of locus D19S394, which is tightly linked to the gene. The association between the alpha 1A calcium channel and familial hemiplegic migraine, and the increase of shared alleles in migraine-affected sib-pairs, have uncovered a new pathway for the pathophysiology of migraine. This finding may provide a rationale for the development of specific prophylactic therapy for migraine and other (paroxysmal) cerebral disorders.

Alleles↗

The quest for migraine genes.

Research into the genetics of migraine remains difficult because of the involvement of polygenetic and environmental factors. The discovery of the gene for familial hemiplegic migraine on chromosome 19p 13 is an important step forward. This brain specific P/Q-type calcium channel alpha 1-subunit gene opens new avenues for studying the genetics of migraine, the pathophysiology of the onset of migraine attacks and the development of novel specific prophylactic drugs.

Family Health↗

Partial cosegregation of familial hemiplegic migraine and a benign familial infantile epileptic syndrome.

PURPOSE: We studied a large Dutch-Canadian family, in which two very rare hereditary paroxysmal neurologic disorders, familial hemiplegic migraine (FHM) and a "benign familial infantile epileptic syndrome" concur and partially cosegregate. FHM is a dominantly inherited subtype of migraine with attacks of hemiparesis, linked to chromosome 19p13 in 50% of the families tested. Recently mutations in a brain-specific P/Q-type Ca2+ channel alpha1 subunit gene (CACNL1A4) were identified in families with chromosome 19-linked FHM. The infantile epileptic syndrome resembles to two other dominantly inherited benign epilepsies occurring in the first year of life, benign familial neonatal convulsions (BFNC), assigned to chromosomes 20q13.2 and 8q, and benign infantile familial convulsions (BIFC), as yet unlinked. METHODS: Linkage analysis was performed for the known locations of FHM and BFNC. The question whether the two conditions in this family can be caused by a single gene defect was addressed by additional linkage analysis. RESULTS: We excluded linkage of the infantile convulsions to markers on chromosome 20q13.2, 8q, or 19p13. This indicates the existence of a third locus for benign familial convulsions in the first year of life. Linkage of FHM to these markers was not formally excluded but seems very unlikely. Statistical analysis of whether, in this family, both conditions are caused by a single gene defect was inconclusive. CONCLUSIONS: We describe a "benign familial infantile epileptic syndrome" with attacks of FHM at a later age. Further genetic studies in this family may help to unravel the genetic basis of epilepsy or migraine or both.

Age of Onset↗

Familial hemiplegic migraine: involvement of a calcium neuronal channel.

A gene for familial hemiplegic migraine (FHM), a subtype of migraine with aura, has been assigned to chromosome 19p13. In this region we identified a brain-specific P/Q-type calcium channel alpha 1A-subunit gene, CACNL1A4, with 47 exons covering 300 kb. Sequencing of all exons and their flanking surroundings revealed polymorphic variations, including a (CA)n-repeat, and a (CAG)n-repeat in the 3'-UTR. In FHM patients, we found four different missense mutations in conserved functional domains. One of the mutations has occurred on two different haplotypes in unrelated FHM families. Moreover, in episodic ataxia type-2 (EA-2), we found two mutations disrupting the reading frame. Thus, FHM and EA-2 can be considered as allelic channelopathies. Involvement of this FHM locus in migraine with and without aura was demonstrated by sib-pair analysis. We showed an increase of shared marker alleles of locus D19S394, which is tightly linked to the gene. The association between the alpha 1A calcium channel and FHM, and the increase of shared alleles in migraine affected sib-pairs, have uncovered a new pathway for the pathophysiology of migraine. This finding may provide a rationale for the development of specific prophylactic therapy for migraine and other (paroxysmal) cerebral disorders.

Calcium Channels↗

Familial hemiplegic migraine and episodic ataxia type-2 are caused by mutations in the Ca2+ channel gene CACNL1A4.

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.

Base Sequence↗

Rizatriptan vs sumatriptan in the acute treatment of migraine. A placebo-controlled, dose-ranging study. Dutch/US Rizatriptan Study Group.

BACKGROUND: Rizatriptan (MK-462) is a new 5-hydroxytryptamine1D (serotonin1D; 5-HT1D) receptor agonist for the acute treatment of migraine that has improved pharmacokinetic properties compared with sumatriptan succinate. OBJECTIVE: To assess the efficacy and tolerability of 10-, 20-, and 40-mg doses of oral rizatriptan vs a 100-mg dose of oral sumatriptan succinate and placebo for the acute treatment of migraine. DESIGN: Randomized, double-blind, parallel-group, placebo-controlled, outpatient trial. SETTING: Ten US and 4 Dutch investigator centers. PATIENTS: Patients who had migraine with or without aura (N = 449). MAIN OUTCOME MEASURE: The proportion of patients whose conditions improved from severe or moderate headache immediately before dosing to mild or no headache at 2 hours after drug administration (ie, headache relief). RESULTS: The proportion of patients with headache relief was 18% for placebo; 46% for sumatriptan; and 52% for 10-mg, 56% for 20-mg, and 67% for 40-mg rizatriptan. All differences with placebo were statistically significant (P < .001), and 40-mg rizatriptan was superior to sumatriptan (P = .01). The proportion of patients who became free of pain at 2 hours was 3% for the placebo-treated group; 22% for the sumatriptan-treated group; and 26%, 35%, and 47% for the group of patients who took the 10-, 20-, and 40-mg doses of rizatriptan, respectively (all differences with placebo, P < .005; 40-mg rizatripan vs sumatriptan, P = .001). The recurrence of headache within 24 hours was found to be equal across all treatment groups-approximately 40%. Adverse events (most commonly short-lasting mild or moderate dizziness and drowsiness) occurred more frequently after a 40-mg dose of rizatriptan was given than after the other treatments. CONCLUSIONS: The antimigraine effect of 10- and 20-mg rizatriptan was superior to placebo, and comparable with that of 100-mg sumatriptan succinate; the efficacy of 40-mg rizatriptan was superior to that of both placebo and 100-mg sumatriptan succinate, although it was associated with a high frequency of adverse events.

Adult↗

Familial hemiplegic migraine: a clinical comparison of families linked and unlinked to chromosome 19.DMG RG.

We compared the clinical characteristics of 46 patients from three unrelated families with familial hemiplegic migraine (FHM) linked to chromosome 19, with those of 20 patients from two families with FHM not linked to chromosome 19. We found no significant differences for age at onset, frequency and duration of attacks, duration of the paresis, and occurrence of basilar migraine symptoms. In the linked families, significantly more patients reported unconsciousness during attacks (39% vs 15%; p < 0.05) and provocation of attacks by mild head trauma (70% vs 40%; p < 0.05). In one linked family patients also displayed chronic progressive cerebellar ataxia, whereas in one unlinked family benign infantile convulsions occurred in addition to FHM. Interestingly, so far an association with cerebellar ataxia was only described in chromosome 19-linked families. FHM linked to chromosome 19 and FHM unlinked to chromosome 19 do not differ with respect to clinical features.

Adolescent↗

A 3-Mb region for the familial hemiplegic migraine locus on 19p13.1-p13.2: exclusion of PRKCSH as a candidate gene. Dutch Migraine Genetic Research Group.

Familial hemiplegic migraine (FHM) is an autosomal domianant subtype of migraine with attacks, associated with transient episodes of hemiparesis. One of the genes for FHM has been assigned to chromosome 19p13. Detailed analysis of critical recombinants from two different chromosome 19-linked FHM families, using new markers indicated a 6-cM candidate region on 19p13.1-p13.2 flanked by loci D19S394 and D19S226. Another paroxysmal neurological disorder, episodic ataxia type 2 (EA-2), has also been linked to the same chromosomal region. Most of the interval was completely covered by YAC and cosmid contigs; the physical map yielded approximately 3 Mb encompassing several genes including the protein kinase substrate 80K-H (PRKCSH) gene. Since PRKCSH is involved in neuronal signal transduction, it was considered to be an FHM candidate gene. The genomic structure of this gene was established and mutation analysis for all exon and flanking intron sequences was performed in FHM- and EA-2-affected individuals. Five polymorphisms were identified, including a trinucleotide repeat length variation in the coding sequence. However, no potential disease causing mutation was found and therefore the PRKCSH gene can be excluded for both FHM and EA-2.

Base Sequence↗

Familial hemiplegic migraine locus on 19p13 is involved in the common forms of migraine with and without aura.

Migraine is a common neurological disease of two main types: migraine with aura and migraine without aura. Familial clustering suggests that genetic factors are involved in the etiology of migraine. Recently, a gene for familial hemiplegic migraine, a rare autosomal dominant subtype of migraine with aura, was mapped to chromosome 19p13. We tested the involvement of this chromosomal region in 28 unrelated families with the common forms of migraine with and without aura, by following the transmission of the highly informative marker D19S394. Sib-pair analysis showed that affected sibs shared the same marker allele more frequently than expected by chance. Our findings thus also suggest the involvement of a gene on 19p13 in the etiology of the common forms of migraine.

Base Sequence↗

Is familial hemiplegic migraine a hereditary form of basilar migraine?

We studied aura symptoms in 83 patients from 6 unrelated families suffering from familial hemiplegic migraine. Fifty-five of the patients reported symptoms that allowed us to categorize them as basilar migraine (BM) patients, in accordance with the International Headache Society (IHS) criteria. In a control group of 33 patients suffering from migraine with aura and 33 patients suffering from migraine without aura, 9 patients complained of vertigo, and only one patient of diplopia during one of her attacks. None of these control patients fulfilled the IHS criteria for BM. We suggest that familial hemiplegic migraine and BM may share certain pathophysiologic mechanisms, which may consist of a (genetically determined) disturbance of basilar artery blood flow.

Adolescent↗