Blood donation and migraine relief: A national population cohort study in Denmark.

INTRODUCTION: Migraine is a prevalent neurological headache disorder. Due to challenges associated with finding effective treatment, many individuals with migraine feel compelled to explore alternative treatment strategies, such as blood donation, hypothesized to provide migraine relief. METHODS: Through logistic, Poisson, and Cox regression methods, we examined the links between migraine and blood donation activities in two population cohorts: Danish blood donors in the Scandinavian Donations and Transfusions Database (SCANDAT-DK, N >1 million) and the Danish Blood Donor Study (N ~ 100,000). RESULTS: SCANDAT-DK analyses showed no link between migraine and the propensity to become a blood donor among males (odds ratio [OR]Males = 0.95 [95% Confidence Interval: 0.86-1.04], and a reduced propensity among females ORFemales = 0.88 [0.83-0.93]). The incidence of migraine was not reduced upon blood donation (standardized incidence ratio [SIR]Males = 0.94 [0.83-1.06]; SIRFemales = 1.04 [0.99-1.10]). Donors with migraine demonstrated longer intervals between donations (hazard ratio [HR]Males = 0.87 [0.85-0.91], HRFemales = 0.80 [0.78-0.82]), and an increased risk of donor lapse (ORMales = 1.23 [1.14-1.32]; ORFemales = 1.28 [1.22-1.33]). Results were corroborated in DBDS using self-reported migraine. Genetic predisposition to migraine associated with longer intervals in females (HRFemales = 0.98 [0.97-0.99]), but not in males. DISCUSSION: Our findings do not support the hypothesis that blood donation serves as a viable treatment strategy among migraine patients. Future prospective investigations may help to elucidate the underlying biological mechanisms by which blood donation may influence migraine pathology.

DNA-methylation and immunological response in medication overuse headache.

OBJECTIVE: To investigate whether medication-overuse headache patients have differential DNA-methylation pattern. METHODS: We collected blood samples from 120 medication-overuse headache-patients, 57 controls (29 episodic migraine patients and 28 healthy controls) in a hypothesis-generating cross-sectional case-control pilot study; 100 of the medication-overuse headache-patients were followed for six months and samples were collected at two and six months for the longitudinal methylation analyses. Blood cell proportions of leucocytes (neutrophils, NK-cells, monocytes, CD8+ and CD4+ T-cells, and B-cells) and the neutrophile-lymphocyte ratio were estimated using methylation data as a measure for immunological analysis and a cell type-specific epigenome wide association study was conducted between medication-overuse headache-patients and controls, and longitudinally for reduction in headache days/month among medication-overuse headache-patients. RESULTS: We found a higher neutrophile-lymphocyte ratio in medication-overuse headache-patients compared to controls, indicating a higher immunological response in medication-overuse headache-patients (false discovery rate (adjusted p-value)<0.001). Reduction in headache days/month (9.8; 95% CI 8.1-11.5) was associated with lower neutrophile-lymphocyte ratio (false discovery rate adjusted p-value = 0.041).Three genes (CORIN, CCKBR and CLDN9) were hypermethylated in specific cell types in medication-overuse headache-patients compared to controls. No methylation differences were associated with reduction in headache days in medication-overuse headache-patients after six months. CONCLUSION: This pilot study was consistent with higher immunological response in medication-overuse headache-patients which decreased with a reduction in headache days in longitudinal analysis. medication-overuse headache-patients exhibited differential methylation in innate immune cells but did not exhibit longitudinal differences with alterations in headache days. Our study creates hypotheses for further biomarker searches.ClinicalTrials.gov Identifier: NCT02993289.

Sex differences in clinical characteristics of migraine and its burden: a population-based study.

BACKGROUND AND PURPOSE: Understanding migraine in a sex-specific manner is crucial for improving clinical care, diagnosis and therapy for both females and males. Here, data on sex differences are provided in the presentation of migraine in a large European-based population cohort, which is representative of the general population. METHODS: A population-based study of 62,672 Danish blood donors (both present and previous donors), of whom 12,658 had migraine, was performed. All participants completed a 105-item diagnostic migraine questionnaire sent via an electronic mailing system (e-Boks) between May 2020 and August 2020. The questionnaire allowed for correct diagnosis of migraine according to the International Classification of Headache Disorders, third edition. RESULTS: The migraine questionnaire was in-cohort validated and had a positive predictive value of 97% for any migraine, a specificity of 93% and a sensitivity of 93%. There were 9184 females (mean age 45.1 years) and 3434 males (mean age 48.0 years). The 3-month prevalence of migraine without aura was 11% in females and 3.59% in males. The 3-month prevalence of migraine with aura was 1.72% in females and 1.58% in males. In females, the age-related 3-month prevalence of migraine without aura increased markedly during childbearing age. In males, migraine both with and without aura showed less age variation. Females had a higher frequency of migraine attacks (odds ratio [OR] 1.22) but a lower frequency of non-migraine headaches (OR = 0.35). Females also had a greater intensity of pain, more unilateral and pulsatile pain, and exacerbation by physical activity (OR = 1.40-1.49) as well as more associated symptoms (OR = 1.26-1.98). Females carried 79% of the total migraine disease burden, which was almost exclusively driven by migraine without aura (77%), whilst there was no sex difference in the disease burden of migraine with aura. CONCLUSION: Females have more severe disease, resulting in a much higher migraine disease burden than indicated by prevalence alone.

Multi-omics to predict changes during cold pressor test.

BACKGROUND: The cold pressor test (CPT) is a widely used pain provocation test to investigate both pain tolerance and cardiovascular responses. We hypothesize, that performing multi-omic analyses during CPT gives the opportunity to home in on molecular mechanisms involved. Twenty-two females were phenotypically assessed before and after a CPT, and blood samples were taken. RNA-Sequencing, steroid profiling and untargeted metabolomics were performed. Each 'omic level was analyzed separately at both single-feature and systems-level (principal component [PCA] and partial least squares [PLS] regression analysis) and all 'omic levels were combined using an integrative multi-omics approach, all using the paired-sample design. RESULTS: We showed that PCA was not able to discriminate time points, while PLS did significantly distinguish time points using metabolomics and/or transcriptomic data, but not using conventional physiological measures. Transcriptomic and metabolomic data revealed at feature-, systems- and integrative- level biologically relevant processes involved during CPT, e.g. lipid metabolism and stress response. CONCLUSION: Multi-omics strategies have a great potential in pain research, both at feature- and systems- level. Therefore, they should be exploited in intervention studies, such as pain provocation tests, to gain knowledge on the biological mechanisms involved in complex traits.

Genetic Susceptibility Loci in Genomewide Association Study of Cluster Headache.

OBJECTIVE: Identifying common genetic variants that confer genetic risk for cluster headache. METHODS: We conducted a case-control study in the Dutch Leiden University Cluster headache neuro-Analysis program (LUCA) study population (n = 840) and unselected controls from the Netherlands Epidemiology of Obesity Study (NEO; n = 1,457). Replication was performed in a Norwegian sample of 144 cases from the Trondheim Cluster headache sample and 1,800 controls from the Nord-Trøndelag Health Survey (HUNT). Gene set and tissue enrichment analyses, blood cell-derived RNA-sequencing of genes around the risk loci and linkage disequilibrium score regression were part of the downstream analyses. RESULTS: An association was found with cluster headache for 4 independent loci (r2 < 0.1) with genomewide significance (p < 5 × 10-8 ), rs11579212 (odds ratio [OR] = 1.51, 95% confidence interval [CI] = 1.33-1.72 near RP11-815 M8.1), rs6541998 (OR = 1.53, 95% CI = 1.37-1.74 near MERTK), rs10184573 (OR = 1.43, 95% CI = 1.26-1.61 near AC093590.1), and rs2499799 (OR = 0.62, 95% CI = 0.54-0.73 near UFL1/FHL5), collectively explaining 7.2% of the variance of cluster headache. SNPs rs11579212, rs10184573, and rs976357, as proxy SNP for rs2499799 (r2  = 1.0), replicated in the Norwegian sample (p < 0.05). Gene-based mapping yielded ASZ1 as possible fifth locus. RNA-sequencing indicated differential expression of POLR1B and TMEM87B in cluster headache patients. INTERPRETATION: This genomewide association study (GWAS) identified and replicated genetic risk loci for cluster headache with effect sizes larger than those typically seen in complex genetic disorders. ANN NEUROL 2021;90:203-216.

Characterization of erenumab and rimegepant on calcitonin gene-related peptide induced responses in Xenopus Laevis oocytes expressing the calcitonin gene-related peptide receptor and the amylin-1 receptor.

BACKGROUND: The clinical use of calcitonin gene-related peptide receptor (CGRP-R) antagonists and monoclonal antibodies against CGRP and CGRP-R has offered new treatment possibilities for migraine patients. CGRP activates both the CGRP-R and structurally related amylin 1 receptor (AMY1-R). The relative effect of erenumab and the small-molecule CGRP-R antagonist, rimegepant, towards the CGRP-R and AMY-R needs to be further characterized. METHODS: The effect of CGRP and two CGRP-R antagonists were examined in Xenopus laevis oocytes expressing human CGRP-R, human AMY1-R and their subunits. RESULTS: CGRP administered to receptor expressing oocytes induced a concentration-dependent increase in current with the order of potency CGRP-R> > AMY1-R > calcitonin receptor (CTR). There was no effect on single components of the CGRP-R; calcitonin receptor-like receptor and receptor activity-modifying protein 1. Amylin was only effective on AMY1-R and CTR. Inhibition potencies (pIC50 values) for erenumab on CGRP induced currents were 10.86 and 9.35 for CGRP-R and AMY1-R, respectively. Rimegepant inhibited CGRP induced currents with pIC50 values of 11.30 and 9.91 for CGRP-R and AMY1-R, respectively. CONCLUSION: Our results demonstrate that erenumab and rimegepant are potent antagonists of CGRP-R and AMY1-R with 32- and 25-times preference for the CGRP-R over the AMY1-R, respectively. It is discussed if this difference in affinity between the two receptors is the likely reason why constipation is a common and serious adverse effect during CGRP-R antagonism but less so with CGRP binding antibodies.

Chronic migraine: Genetics or environment?

BACKGROUND: The transition from episodic migraine to chronic migraine, migraine chronification, is usually a gradual process, which involves multiple risk factors. To date, studies of the genetic risk factors for chronic migraine have focused primarily on candidate-gene approaches using healthy individuals as controls. AIMS AND METHODS: In this study, we used a large cohort of migraine families and unrelated migraine patients (n > 2200) with supporting genotype and whole-genome sequencing data. We evaluated whether there are any genetic variants, common or rare, with a specific association to chronic migraine compared with episodic migraine. RESULTS: We found no aggregation of chronic migraine in families with a clustering of migraine. No specific rare variants gave rise to migraine chronification, and migraine chronification was not associated with a higher polygenic risk score. Migraine chronification was not associated with allelic associations with an odds ratio above 2.65. Assessment of effect sizes with genome-wide significance below an odds ratio of 2.65 requires a genome-wide association study of at least 7500 chronic migraine patients. CONCLUSION: Our results suggest that migraine chronification is caused by environmental factors rather than genetic factors.

Functional gene networks reveal distinct mechanisms segregating in migraine families.

Migraine is the most common neurological disorder worldwide and it has been shown to have complex polygenic origins with a heritability of estimated 40-70%. Both common and rare genetic variants are believed to underlie the pathophysiology of the prevalent types of migraine, migraine with typical aura and migraine without aura. However, only common variants have been identified so far. Here we identify for the first time a gene module with rare mutations through a systems genetics approach integrating RNA sequencing data from brain and vascular tissues likely to be involved in migraine pathology in combination with whole genome sequencing of 117 migraine families. We found a gene module in the visual cortex, based on single nuclei RNA sequencing data, that had increased rare mutations in the migraine families and replicated this in a second independent cohort of 1930 patients. This module was mainly expressed by interneurons, pyramidal CA1, and pyramidal SS cells, and pathway analysis showed association with hormonal signalling (thyrotropin-releasing hormone receptor and oxytocin receptor signalling pathways), Alzheimer's disease pathway, serotonin receptor pathway and general heterotrimeric G-protein signalling pathways. Our results demonstrate that rare functional gene variants are strongly implicated in the pathophysiology of migraine. Furthermore, we anticipate that the results can be used to explain the critical mechanisms behind migraine and potentially improving the treatment regime for migraine patients.

Familial analysis reveals rare risk variants for migraine in regulatory regions.

The most recent genome-wide association study of migraine increased the total number of known migraine risk loci to 38. Still, most of the heritability of migraine remains unexplained, and it has been suggested that rare gene dysregulatory variants play an important role in migraine etiology. Addressing the missing heritability of migraine, we aim to fine-map signals from the known migraine risk loci to regulatory mechanisms and associate these to downstream genic targets. We analyzed a large cohort of whole-genome sequenced patients from extended migraine pedigrees (1040 individuals from 155 families). We test for association between rare variants segregating in regulatory regions with migraine. The findings were replicated in an independent case-control cohort (2027 migraineurs, 1650 controls). We report an increased burden of rare variants in one CpG island and three polycomb group response elements near four migraine risk loci. We found that the association is independent of the common risk variants in the loci. The regulatory regions are suggested to affect different genes than those originally tagged by the index SNPs of the migraine loci. Families with familial clustering of migraine have an increased burden of rare variants in regulatory regions near known migraine risk loci, with effects that are independent of the variants in the loci. The possible regulatory targets suggest different genes than those originally tagged by the index SNPs of the migraine loci.

Characterization of eQTLs associated with androstenone by RNA sequencing in porcine testis.

Characterization of genetic variants affecting genome-wide gene expression levels (expression quantitative trait loci or eQTLs) in pig testes may improve our understanding of genetic architecture of boar taint (an animal welfare trait) and helps in genome-assisted or genomic selection programs. The aims of this study were to identify eQTLs associated with androstenone, to find candidate eQTLs for low androstenone, and to validate the top eQTL by reverse transcriptase quantitative PCR (RT-qPCR). Gene expression profiles were obtained by RNA sequencing in testis from Danish cross-bred pigs and genotype data by 80K single nucleotide polymorphism panel. A total of 262 eQTLs [false discovery rate (FDR) < 0.05] were identified by using two software packages: Matrix eQTL and Krux eQTL. Of these, 149 cis-acting eQTLs were significantly associated with androstenone concentrations and gene expression (FDR < 0.05). The eQTLs were associated with several genes of boar taint relevance including CYP1A2, CYB5D1, and SPHK2. One eQTL gene, AMPH, was differentially expressed (FDR < 0.05) and affected by chicory. Five candidate eQTLs associated with low androstenone concentrations were discovered, including the top eQTL associated with CYP1A2. RT-qPCR confirmed target gene expression to be significantly (P < 0.05) different based on eQTL genotypes. Furthermore, eQTLs were enriched as QTLs for 15 boar taint related traits from the PigQTLdb. This is the first study to report eQTLs in testes of commercial crossbred pigs used in pork production and to reveal genetic architecture of boar taint. Potential applications include development of a DNA test and in advanced genomic selection models for boar taint.

Characterization of Familial and Sporadic Migraine.

BACKGROUND: It is unknown whether clinical parameters differ between migraineurs with and without first-degree family members with migraine. OBJECTIVES: The present cross-sectional study describes differences between familial and sporadic migraine with a focus on migraine characteristics, migraine severity, comorbidities, and treatment. METHOD: From the Danish Headache Center we recruited 358 patients with familial migraine and 1727 patients with sporadic migraine. Each participant was assessed using a validated semi-structured interview. RESULTS: No differences in age (Mean = 44 and 44 [SD = 12.28 and 12.58] for familial and sporadic migraineurs, respectively; P = .900) or sex (295/358 (82.4%) and 1413/1727 (81.8%) women in familial and sporadic migraineurs, respectively; P = .853) were found. Familial migraineurs had more aphasic aura than sporadic migraineurs (41% vs 27%, P = .001). Sporadic migraineurs had more lifetime attacks ie, >100 attacks (45% vs 70%, P < .001) and prolonged attacks ie, lasting >72 hours (5% vs 12%, P < .001) than familial migraineurs. Further, sporadic migraineurs had a higher incidence of concussions (37% vs 41%, P = .001) compared to familial migraineurs. In agreement with a previous study, there was no difference between familial and sporadic migraine regarding triptan response (84% vs 81%, P = .440). CONCLUSION: Headache characteristics, triptan response, and comorbidities where similar in individulas with and without inherited migraine, suggesting that migraine are to be considered a hmogenoues disease. The difference in the clinical presentation of migraine with aura symptoms among patients with familial migraine should be considered in future studies. Further, more severe migraine among patients with sporadic migraine with aura could suggest that sporadic migraineurs have been exposed to stronger or multiple environmental factors and indicate that an early intervention in migraine treatment could lessen the severity of migraine.

WISH-R- a fast and efficient tool for construction of epistatic networks for complex traits and diseases.

BACKGROUND: Genetic epistasis is an often-overlooked area in the study of the genomics of complex traits. Genome-wide association studies are a useful tool for revealing potential causal genetic variants, but in this context, epistasis is generally ignored. Data complexity and interpretation issues make it difficult to process and interpret epistasis. As the number of interaction grows exponentially with the number of variants, computational limitation is a bottleneck. Gene Network based strategies have been successful in integrating biological data and identifying relevant hub genes and pathways related to complex traits. In this study, epistatic interactions and network-based analysis are combined in the Weighted Interaction SNP hub (WISH) method and implemented in an efficient and easy to use R package. RESULTS: The WISH R package (WISH-R) was developed to calculate epistatic interactions on a genome-wide level based on genomic data. It is easy to use and install, and works on regular genomic data. The package filters data based on linkage disequilibrium and calculates epistatic interaction coefficients between SNP pairs based on a parallelized efficient linear model and generalized linear model implementations. Normalized epistatic coefficients are analyzed in a network framework, alleviating multiple testing issues and integrating biological signal to identify modules and pathways related to complex traits. Functions for visualizing results and testing runtimes are also provided. CONCLUSION: The WISH-R package is an efficient implementation for analyzing genome-wide epistasis for complex diseases and traits. It includes methods and strategies for analyzing epistasis from initial data filtering until final data interpretation. WISH offers a new way to analyze genomic data by combining epistasis and network based analysis in one method and provides options for visualizations. This alleviates many of the existing hurdles in the analysis of genomic interactions.

Transcription Factor Co-expression Networks of Adipose RNA-Seq Data Reveal Regulatory Mechanisms of Obesity.

BACKGROUND: Transcription Factors (TFs) control actuation of genes in the genome and are key mediators of complex processes such as obesity. Master Regulators (MRs) are the genes at the top of a regulation hierarchy which regulate other genes. OBJECTIVE: To elucidate clusters of highly co-expressed TFs (modules), involved pathways, highly inter-connected TFs (hub-TFs) and MRs leading to obesity and leanness, using porcine model for human obesity. METHODS: We identified 817 expressed TFs in RNA-Sequencing dataset representing extreme degrees of obesity (DO; lean, obese). We built a single Weighted Transcription Factor Co-expression Network (WTFCN) and TF sub-networks (based on the DO). Hub-TFs and MRs (using iRegulon) were identi-fied in biologically relevant WTFCNs modules. RESULTS: Single WTFCN detected the Red module significantly associated with DO (P < 0.03). This module was enriched for regulation processes in the immune system, e.g.: Immune system process (Padj = 2.50E-06) and metabolic lifestyle disorders, e.g. Circadian rhythm - mammal pathway (Padj = 2.33E-11). Detected MR, hub-TF SPI1 was involved in obesity, immunity and osteoporosis. Within the obese sub-network, the Red module suggested possible associations with immunity, e.g. TGF-beta signaling pathway (Padj = 1.73E-02) and osteoporosis, e.g. Osteoclast differentiation (Padj = 1.94E-02). Within the lean sub-network, the Magenta module displayed associations with type 2 diabetes, obesity and os-teoporosis e.g. Notch signaling pathway (Padj = 2.40E-03), osteoporosis e.g. hub-TF VDR (a prime candidate gene for osteoporosis). CONCLUSION: Our results provide insights into the regulatory network of TFs and biologically relevant hub TFs in obesity.

Multi-omic data integration and analysis using systems genomics approaches: methods and applications in animal production, health and welfare.

In the past years, there has been a remarkable development of high-throughput omics (HTO) technologies such as genomics, epigenomics, transcriptomics, proteomics and metabolomics across all facets of biology. This has spearheaded the progress of the systems biology era, including applications on animal production and health traits. However, notwithstanding these new HTO technologies, there remains an emerging challenge in data analysis. On the one hand, different HTO technologies judged on their own merit are appropriate for the identification of disease-causing genes, biomarkers for prevention and drug targets for the treatment of diseases and for individualized genomic predictions of performance or disease risks. On the other hand, integration of multi-omic data and joint modelling and analyses are very powerful and accurate to understand the systems biology of healthy and sustainable production of animals. We present an overview of current and emerging HTO technologies each with a focus on their applications in animal and veterinary sciences before introducing an integrative systems genomics framework for analysing and integrating multi-omic data towards improved animal production, health and welfare. We conclude that there are big challenges in multi-omic data integration, modelling and systems-level analyses, particularly with the fast emerging HTO technologies. We highlight existing and emerging systems genomics approaches and discuss how they contribute to our understanding of the biology of complex traits or diseases and holistic improvement of production performance, disease resistance and welfare.

Liver transcriptomic networks reveal main biological processes associated with feed efficiency in beef cattle.

BACKGROUND: The selection of beef cattle for feed efficiency (FE) traits is very important not only for productive and economic efficiency but also for reduced environmental impact of livestock. Considering that FE is multifactorial and expensive to measure, the aim of this study was to identify biological functions and regulatory genes associated with this phenotype. RESULTS: Eight genes were differentially expressed between high and low feed efficient animals (HFE and LFE, respectively). Co-expression analyses identified 34 gene modules of which 4 were strongly associated with FE traits. They were mainly enriched for inflammatory response or inflammation-related terms. We also identified 463 differentially co-expressed genes which were functionally enriched for immune response and lipid metabolism. A total of 8 key regulators of gene expression profiles affecting FE were found. The LFE animals had higher feed intake and increased subcutaneous and visceral fat deposition. In addition, LFE animals showed higher levels of serum cholesterol and liver injury biomarker GGT. Histopathology of the liver showed higher percentage of periportal inflammation with mononuclear infiltrate. CONCLUSION: Liver transcriptomic network analysis coupled with other results demonstrated that LFE animals present altered lipid metabolism and increased hepatic periportal lesions associated with an inflammatory response composed mainly by mononuclear cells. We are now focusing to identify the causes of increased liver lesions in LFE animals.

Genome-wide association study reveals a locus in ADARB2 for complete freedom from headache in Danish Blood Donors.

Headache disorders are the most common disorders of the nervous system. The lifetime prevalence of headache disorders show that some individuals never experience headache. The etiology of complete freedom from headache is not known. To assess genetic variants associated with complete freedom from headache, we performed a genome-wide association study of individuals who have never experienced a headache. We included 63,992 individuals (2,998 individuals with complete freedom from headache and 60,994 controls) from the Danish Blood Donor Study Genomic Cohort. Participants were included in two rounds, from 2015 to 2018 and in 2020. We discovered a genome-wide significant association, with the lead variant rs7904615[G] in ADARB2 (EAF = 27%, OR = 1.20 [1.13-1.27], p = 3.92 × 10-9). The genomic locus was replicated in a non-overlapping cohort of 13,032 individuals (539 individuals with complete freedom from headache and 12,493 controls) from the Danish Blood Donor Study Genomic Cohort (p < 0.05, two-sided). Participants for the replication were included from 2015 to 2020. In conclusion, we show that complete freedom from headache has a genetic component, and we suggest that ADARB2 is involved in complete freedom from headache. The genomic locus was specific for complete freedom from headache and was not associated with any primary headache disorders.

Multi-omic analyses of triptan-treated migraine attacks gives insight into molecular mechanisms.

Migraine is a common, polygenic disorder that is characterized by moderate to severe headache attacks. Migraine attacks are commonly treated with triptans, i.e. serotonin receptor agonists. However, triptans are effective in ~ 60% of the population, and the mechanisms of triptans are debated. Here, we aim to expose the mechanisms of triptan using metabolomics and transcriptomics in spontaneous migraine attacks. We collected temporal multi-omics profiles on 24 migraine patients, using samples collected at a migraine attack, 2 h after treatment with a triptan, when headache-free, and after a cold-pressor test. Differential metabolomic analysis was performed to find metabolites associated with treatment. Their effect was further investigated using correlation analysis and a machine learning approach. We found three differential metabolites: cortisol, sumatriptan and glutamine. The change in sumatriptan levels correlated with a change in GNAI1 and VIPR2 gene expression, both known to regulate cAMP levels. Furthermore, we found fatty acid oxidation to be affected, a mechanism known to be involved in migraine but not previously found in relation to triptans. In conclusion, using an integrative approach we find evidence for a role of glutamine, cAMP regulation, and fatty acid oxidation in the molecular mechanisms of migraine and/or the effect of triptans.

Population-Based Characterization of Menstrual Migraine and Proposed Diagnostic Criteria.

Importance: There is a need for better recognition and more extensive research into menstrual migraine (MM) in the general population, and a revision of the diagnostic criteria for MM is warranted to move the field forward. Increased understanding of MM is crucial for improving clinical care, diagnosis, and therapy for MM. Objectives: To assess the clinical characteristics of MM, including severity and treatment response, and to propose new diagnostic criteria for pure MM and menstrually related migraine. Design, Setting, and Participants: This is a case-control study of Danish individuals with migraine. All individuals completed a 105-item validated diagnostic migraine questionnaire, sent via the Danish electronic mailing system (e-Boks) between May and August 2020, allowing diagnosis of pure MM and menstrually related migraine by the International Classification of Headache Disorders, Third Edition (ICHD-3). Data analysis was performed from September 2021 to November 2022. Exposure: Diagnosis of migraine. Main Outcomes and Measures: Clinical characteristics of women with MM and women with nonmenstrual migraine (non-MM) were compared using the ICHD-3 diagnostic criteria. A simulation of the risk of randomly misclassifying MM was based on number of migraine attacks during 3 menstrual cycles (3 × 28 days), and simulation analyses were performed using 100 000 permutations of random migraine attacks in migraine patients. Results: A total of 12 618 individuals, including 9184 women, with migraine participated in the study. Among the women with migraine, the prevalence of MM was 16.6% (1532 women), and the prevalence of non-MM was 45.9% (4216 women). The mean (SD) age was 38.7 (8.7) years for women with MM and 37.0 (9.2) years for women with non-MM. Of the 1532 women with MM, 410 (26.8%) fulfilled ICHD-3 diagnostic criteria for pure MM, 1037 (67.7%) fulfilled ICHD-3 diagnostic criteria for menstrually related migraine, and 152 (9.9%) fulfilled proposed diagnostic criteria for rare pure MM. MM was associated with a higher frequency of migraine-accompanying symptoms (odds ratio [OR], 1.98; 95% CI, 1.71-2.29), more frequent (OR, 7.21; 95% CI, 5.77-9.03) and more severe (OR, 1.17; 95% CI, 1.13-1.21) migraine attacks, lower frequency of nonmigraine headache (OR, 0.31; 95% CI, 0.18-0.49), an overall greater response to treatment with triptans (OR, 1.66; 95% CI, 1.24-2.24), better improvement of migraine attacks during late pregnancy (OR, 5.10; 95% CI, 2.17-14.00), and faster reappearance of migraine attacks post partum (OR, 3.19; 95% CI, 2.40-4.25). Hormonal contraceptive-related MM was associated with a higher prevalence of migraine without aura than migraine related to spontaneous menstruation (OR, 1.82; 95% CI, 1.62-2.06). Otherwise, no differences between hormonal and spontaneous MM were observed. The risk of random diagnostic misclassification of ICHD-3 menstrually related migraine in women with high frequency episodic migraine was 43%. This risk was reduced to 3% when applying the proposed criteria for menstrually related migraine. Conclusions and Relevance: In this case-control study, MM in the general population had clinical characteristics that were quantitively different from those of non-MM. Detailed descriptive data and suggested improved diagnostic criteria for pure MM and menstrually related migraine were provided.

DanMAC5: a browser of aggregated sequence variants from 8,671 whole genome sequenced Danish individuals.

OBJECTIVES: Allele counts of sequence variants obtained by whole genome sequencing (WGS) often play a central role in interpreting the results of genetic and genomic research. However, such variant counts are not readily available for individuals in the Danish population. Here, we present a dataset with allele counts for sequence variants (single nucleotide variants (SNVs) and indels) identified from WGS of 8,671 (5,418 females) individuals from the Danish population. The data resource is based on WGS data from three independent research projects aimed at assessing genetic risk factors for cardiovascular, psychiatric, and headache disorders. To enable the sharing of information on sequence variation in Danish individuals, we created summarized statistics on allele counts from anonymized data and made them available through the European Genome-phenome Archive (EGA, https://identifiers.org/ega. DATASET: EGAD00001009756 ) and in a dedicated browser, DanMAC5 (available at www.danmac5.dk ). The summary level data and the DanMAC5 browser provide insight into the allelic spectrum of sequence variants segregating in the Danish population, which is important in variant interpretation. DATA DESCRIPTION: Three WGS datasets with an average coverage of 30x were processed independently using the same quality control pipeline. Subsequently, we summarized, filtered, and merged allele counts to create a high-quality summary level dataset of sequence variants.

Rare variants with large effects provide functional insights into the pathology of migraine subtypes, with and without aura.

Migraine is a complex neurovascular disease with a range of severity and symptoms, yet mostly studied as one phenotype in genome-wide association studies (GWAS). Here we combine large GWAS datasets from six European populations to study the main migraine subtypes, migraine with aura (MA) and migraine without aura (MO). We identified four new MA-associated variants (in PRRT2, PALMD, ABO and LRRK2) and classified 13 MO-associated variants. Rare variants with large effects highlight three genes. A rare frameshift variant in brain-expressed PRRT2 confers large risk of MA and epilepsy, but not MO. A burden test of rare loss-of-function variants in SCN11A, encoding a neuron-expressed sodium channel with a key role in pain sensation, shows strong protection against migraine. Finally, a rare variant with cis-regulatory effects on KCNK5 confers large protection against migraine and brain aneurysms. Our findings offer new insights with therapeutic potential into the complex biology of migraine and its subtypes.