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The genetic architecture of common traits, including the number, frequency, and effect sizes of inherited variants that contribute to individual risk, has been long debated. Genome-wide association studies have identified scores of common variants associated with type 2 diabetes, but in aggregate, these explain only a fraction of the heritability of this disease. Here, to test the hypothesis that lower-frequency variants explain much of the remainder, the GoT2D and T2D-GENES consortia performed whole-genome sequencing in 2,657 European individuals with and without diabetes, and exome sequencing in 12,940 individuals from five ancestry groups. To increase statistical power, we expanded the sample size via genotyping and imputation in a further 111,548 subjects. Variants associated with type 2 diabetes after sequencing were overwhelmingly common and most fell within regions previously identified by genome-wide association studies. Comprehensive enumeration of sequence variation is necessary to identify functional alleles that provide important clues to disease pathophysiology, but large-scale sequencing does not support the idea that lower-frequency variants have a major role in predisposition to type 2 diabetes.

Immunological hallmarks of multiple sclerosis include the production of antibodies in the central nervous system, expressed as presence of oligoclonal bands and/or an increased immunoglobulin G index-the level of immunoglobulin G in the cerebrospinal fluid compared to serum. However, the underlying differences between oligoclonal band-positive and -negative patients with multiple sclerosis and reasons for variability in immunoglobulin G index are not known. To identify genetic factors influencing the variation in the antibody levels in the cerebrospinal fluid in multiple sclerosis, we have performed a genome-wide association screen in patients collected from nine countries for two traits, presence or absence of oligoclonal bands (n = 3026) and immunoglobulin G index levels (n = 938), followed by a replication in 3891 additional patients. We replicate previously suggested association signals for oligoclonal band status in the major histocompatibility complex region for the rs9271640*A-rs6457617*G haplotype, correlated with HLA-DRB1*1501, and rs34083746*G, correlated with HLA-DQA1*0301 (P comparing two haplotypes = 8.88 × 10(-16)). Furthermore, we identify a novel association signal of rs9807334, near the ELAC1/SMAD4 genes, for oligoclonal band status (P = 8.45 × 10(-7)). The previously reported association of the immunoglobulin heavy chain locus with immunoglobulin G index reaches strong evidence for association in this data set (P = 3.79 × 10(-37)). We identify two novel associations in the major histocompatibility complex region with immunoglobulin G index: the rs9271640*A-rs6457617*G haplotype (P = 1.59 × 10(-22)), shared with oligoclonal band status, and an additional independent effect of rs6457617*G (P = 3.68 × 10(-6)). Variants identified in this study account for up to 2-fold differences in the odds of being oligoclonal band positive and 7.75% of the variation in immunoglobulin G index. Both traits are associated with clinical features of disease such as female gender, age at onset and severity. This is the largest study population so far investigated for the genetic influence on antibody levels in the cerebrospinal fluid in multiple sclerosis, including 6950 patients. We confirm that genetic factors underlie these antibody levels and identify both the major histocompatibility complex and immunoglobulin heavy chain region as major determinants., (© The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis.

Purpose: To study the stigma of epilepsy in a European sample., Methods: Clinical and demographic details and information about patient-perceived stigma was collected by using self-completed questionnaires mailed to members of epilepsy support groups., Results: Stigma data were collected from >5,000 patients living in 15 countries in Europe. Fifty-one percent reported feeling stigmatised, with 18% reporting feeling highly stigmatised. High scores were correlated with worry, negative feelings about life, long-term health problems, injuries, and reported side effects of antiepileptic drugs (AEDs). Cross-cultural comparisons revealed significant differences between countries. A multivariate analysis identified impact of epilepsy, age of onset, country of origin, feelings about life, and injuries associated with epilepsy as significant contributors on scores on the stigma scale., Conclusions: This study confirms the findings of previous studies that have identified the importance of both clinical and nonclinical factors in understanding the stigma of epilepsy. The results of cross-cultural differences require further explanation, and much more research should be conducted to reduce the stigma associated with epilepsy.

Purpose: To examine between-country differences in health-related quality of life (HRQOL) of adults with epilepsy across a large number of European countries., Methods: Self-completion postal questionnaire sent to large sample of adults with epilepsy, recruited from epilepsy support groups or epilepsy outpatient clinics. The questionnaire was developed in English and translated. Back-translations from each language were checked for accuracy. The questionnaire sought information on clinical and socio-demographic details, and contained a number of previously validated scales of psychosocial well-being (the SF-36, the perceived impact of epilepsy scale, and a feelings of stigma scale)., Results: Controlling for socio-demographic and clinical characteristics, significant between-country differences were found in scores on the perceived impact of epilepsy scale, on seven of the eight SF-36 domains, and on the feelings of stigma scale. Respondents in Spain and the Netherlands fared consistently better, whilst those in France fared poorest, compared to those in other countries in terms of the various HRQOL measures used., Conclusion: Several possible reasons for the cross-cultural differences in HRQOL are proposed. Clearly, there is no single explanation and there may also be reasons which we have overlooked. This study emphasises the need for further comprehensive research in order that the position of people with epilepsy in different countries be more thoroughly understood in the social context.

A considerable literature is now available on the applications and psychometric properties of the MOS SF-36 Health Survey. In epilepsy, the SF-36 has been used as a health status measure in its own right and as the stem for two condition-specific measures. This paper replicates for epilepsy previous work to support use of the SF-36 across a range of clinical conditions. Data were obtained from a European-wide descriptive study of quality of life of adults with epilepsy; analysis of responses on the SF-36 is based on 4,929 subjects in eight countries. Missing value rates for all SF-36 items were low; percentages for whom complete information available for subscales ranged from 95.7% to 98.6%. All subscales passed tests for item-internal consistency and item-discriminant validity. Reliability coefficients exceeded the standard recommended for group comparisons across all subscales. Floor effects were negligible for all but the two role disability subscales; there were substantial ceiling effects for five of the SF-36 subscales. We conclude that the SF-36 is a valid and reliable health status measure for descriptive studies of people with epilepsy, but ceiling effects may limit its usefulness as an outcome measure in the assessment of new treatments.

Purpose: To study the impact of epilepsy and its treatment on people with epilepsy in Europe. We therefore aimed to collect data from as many countries as possible., Methods: Clinical and demographic details and information about psychosocial functioning was collected using self-completed questionnaires mailed to members of epilepsy support groups., Results: Quality of life data was collected from >5,000 patients living in 15 countries in Europe. Over a third of all respondents had frequent seizures, and a fifth believed that their seizures were not well enough controlled by antiepileptic medication. Reported levels of side effects from medication were high. A significant number of respondents reported changing their medication because of side effects or poor control. Respondents reported that epilepsy and its treatment had a significant impact on a number of different aspects of their daily lives. Half of all respondents felt stigmatised by their epilepsy. There were significant differences by seizure type and frequency in the way respondents scored on measures of the perceived impact of their condition, the stigma associated with it and their health status as measured by a generic scale, the SF36., Conclusions: This study confirms the findings of previous smaller-scale studies that reducing side effects and achieving better control of seizures are key to improving the quality of life of people with epilepsy, as is reducing the stigma and handicap associated with it.