Hemiplegic migraine (HM) is a rare subtype of migraine with aura. Given that causal missense mutations in the voltage-gated calcium channel α1A subunit gene CACNA1A have been identified in a... Show moreHemiplegic migraine (HM) is a rare subtype of migraine with aura. Given that causal missense mutations in the voltage-gated calcium channel α1A subunit gene CACNA1A have been identified in a subset of HM patients, we investigated whether HM patients without a mutation have an increased burden of such variants in the “CACNA1x gene family”. Whole exome sequencing data of an Australian cohort of unrelated HM patients (n = 184), along with public data from gnomAD, as controls, was used to assess the burden of missense variants in CACNA1x genes. We performed both a variant and a subject burden test. We found a significant burden for the number of variants in CACNA1E (p = 1.3 × 10−4), CACNA1H (p < 2.2 × 10−16) and CACNA1I (p < 2.2 × 10−16). There was also a significant burden of subjects with missense variants in CACNA1E (p = 6.2 × 10−3), CACNA1H (p < 2.2 × 10−16) and CACNA1I (p < 2.2 × 10−16). Both the number of variants and number of subjects were replicated for CACNA1H (p = 3.5 × 10−8; p = 0.012) and CACNA1I (p = 0.019, p = 0.044), respectively, in a Dutch clinical HM cohort (n = 32), albeit that CACNA1I did not remain significant after multiple testing correction. Our data suggest that HM, in the absence of a single causal mutation, is a complex trait, in which an increased burden of missense variants in CACNA1H and CACNA1I may contribute to the risk of disease. Show less
This thesis explores clinical phenotypes and the pathophysiology of rare monogenic models of migraine with the ultimate goal to identify novel treatment targets for these disorders, as well as for... Show moreThis thesis explores clinical phenotypes and the pathophysiology of rare monogenic models of migraine with the ultimate goal to identify novel treatment targets for these disorders, as well as for the common types of migraine. The research is divided in two parts: part one describes studies on hemiplegic migraine (HM), a monogenic form of migraine, part two describes studies on Retinal Vasculopathy with Cerebral Leukoencephalopathy and Systemic manifestations (RVCL-S), a monogenic vascular syndrome hypothesised to be associated with migraine. Show less
Background Patients with hemiplegic migraine (HM) may sometimes develop progressive neurological deterioration of which the pathophysiology is unknown.Patient We report a 16-year clinical and... Show moreBackground Patients with hemiplegic migraine (HM) may sometimes develop progressive neurological deterioration of which the pathophysiology is unknown.Patient We report a 16-year clinical and neuroradiological follow-up of a patient carrying a de novo p.Ser218Leu CACNA1A HM mutation who had nine severe HM attacks associated with seizures and decreased consciousness between the ages of 3 and 12 years.Results Repeated ictal and postictal neuroimaging revealed cytotoxic oedema during severe HM attacks in the symptomatic hemisphere, which later showed atrophic changes. In addition, progressive cerebellar atrophy was observed. Brain atrophy halted after cessation of severe attacks, possibly due to prophylactic treatment with flunarizine and sodium valproate.Conclusion Severe HM attacks may result in brain atrophy and prophylactic treatment of these attacks might be needed in an early stage of disease to prevent permanent brain damage. Show less
The aim of the studies described in this thesis was to investigate how abnormal CaV2.1 channel function can cause disease, in particular motor coordination dysfunction. The chapters illustrate how... Show moreThe aim of the studies described in this thesis was to investigate how abnormal CaV2.1 channel function can cause disease, in particular motor coordination dysfunction. The chapters illustrate how various neuronal cell types in the periphery (peripheral nervous system) and the central nervous system are affected by mutations in subunits of CaV2.1 channels. Using existing and newly generated mouse models, the consequences of such mutations were investigated at the molecular, cellular, and systems level so as to unravel pathways involved in motor coordination. Show less
