Genome-wide association studies (GWASs) have been effective approaches to dissect common genetic variability underlying complex diseases in a systematic and unbiased way. Recently, GWASs have led to the discovery of over 20 susceptibility loci for Alzheimer's disease (AD). Despite the evidence showing the contribution of these loci to AD pathogenesis, their genetic architecture has not been extensively investigated, leaving the possibility that low frequency and rare coding variants may also occur and contribute to the risk of disease. We have used exome and genome sequencing data to analyze the single independent and joint effect of rare and low-frequency protein coding variants in 9 AD GWAS loci with the strongest effect sizes after APOE (BIN1, CLU, CR1, PICALM, MS4A6A, ABCA7, EPHA1, CD33, and CD2AP) in a cohort of 332 sporadic AD cases and 676 elderly controls of British and North-American ancestry. We identified coding variability in ABCA7 as contributing to AD risk. This locus harbors a low-frequency coding variant (p.G215S, rs72973581, minor allele frequency = 4.3%) conferring a modest but statistically significant protection against AD (p-value = 0.024, odds ratio = 0.57, 95% confidence interval = 0.41–0.80). Notably, our results are not driven by an enrichment of loss of function variants in ABCA7, recently reported as main pathogenic factor underlying AD risk at this locus. In summary, our study confirms the role of ABCA7 in AD and provides new insights that should address functional studies.
We have screened sporadic early-onset Alzheimer’s disease (sEOAD, n = 408) samples using the NeuroX array for known causative and predicted pathogenic variants in 16 genes linked to familial forms of neurodegeneration. We found 2 sEOAD individuals harboring a known causative variant in PARK2 known to cause early-onset Parkinson’s disease; p.T240M (n = 1) and p.Q34fs delAG (n = 1). In addition, we identified 3 sEOAD individuals harboring a predicted pathogenic variant in MAPT (p.A469T), which has previously been associated with AD. It is currently unknown if these variants affect susceptibility to sEOAD, further studies would be needed to establish this. This work highlights the need to screen sEOAD individuals for variants that are more classically attributed to other forms of neurodegeneration.
A number of genetic loci associate with early onset Alzheimer’s disease (EOAD); however, the drivers of this disease remains enigmatic. Genome wide association and in vivo modeling have shown that loss-of-function, e.g., ABCA7, reduced levels of SIRT1 and MEFF2C, or increased levels of PTK2β confer risk or link to the pathogenies. It is known that DNA methylation can profoundly affect gene expression and can impact on the composition of the proteome; therefore, the aim of this study is to assess if genes associated with sporadic EOAD (sEOAD) are differentially methylated. Epi-profiles of DNA extracted from blood and cortex were compared using a pyrosequencing platform. We identified significant group-wide hypomethylation in AD blood when compared to controls for 7 CpGs located within the 3’UTR of RIN3 (CpG1 p = 0.019, CpG2 p = 0.018, CpG3 p = 0.012, CpG4 p = 0.009, CpG5 p = 0.002, CpG6 p = 0.018, and CpG7 p = 0.013, respectively; AD/Control n = 22/26; Male/Female n = 27/21). Observed effects were not gender specific. No group wide significant differences were found in the promoter methylation of PTK2β, ABCA7, SIRT1, or MEF2C, genes known to associate with late onset AD. A rare and significant difference in methylation was observed for one CpG located upstream of the MEF2C promoter in one AD individual only (22% reduction in methylation, p = 2.0E-10; Control n = 26, AD n = 25, Male/Female n = 29/22). It is plausible aberrant methylation may mark sEOAD in blood and may manifest in some individuals as rare epi-variants for genes linked to sEOAD.
ObjectiveTo evaluate the current provision and outcome of community-based education (CBE) in UK medical schools.Design and data sourcesAn online survey of UK medical school websites and course prospectuses and a systematic review of articles from PubMed and Web of Science were conducted. Articles in the systematic review were assessed using Rossi, Lipsey and Freeman's approach to programme evaluation.Study selectionPublications from November 1998 to 2013 containing information related to community teaching in undergraduate medical courses were included.ResultsOut of the 32 undergraduate UK medical schools, one was excluded due to the lack of course specifications available online. Analysis of the remaining 31 medical schools showed that a variety of CBE models are utilised in medical schools across the UK. Twenty-eight medical schools (90.3%) provide CBE in some form by the end of the first year of undergraduate training, and 29 medical schools (93.5%) by the end of the second year. From the 1378 references identified, 29 papers met the inclusion criteria for assessment. It was found that CBE mostly provided advantages to students as well as other participants, including GP tutors and patients. However, there were a few concerns regarding the lack of GP tutors’ knowledge in specialty areas, the negative impact that CBE may have on the delivery of health service in education settings and the cost of CBE.ConclusionsDespite the wide variations in implementation, community teaching was found to be mostly beneficial. To ensure the relevance of CBE for ‘Tomorrow's Doctors’, a national framework should be established, and solutions sought to reduce the impact of the challenges within CBE.Strengths and limitations of this studyThis is the first study to review how community-based education is currently provided throughout Medical Schools in the UK. The use of Rossi, Lipsey and Freeman's method of programme evaluation means that the literature was analysed in a consistent and comprehensive way. However, a weakness is that data from the online survey was obtained from online medical school prospectuses. This means the data may be incomplete or out of date. Data in the literature review may also be skewed by publication bias.
At present, evidence is insufficient to support or refute the use of metformin alone or in combination with standard therapy - specifically, megestrol acetate - versus megestrol acetate alone, for treatment of endometrial hyperplasia. Robustly designed and adequately powered randomised controlled trials yielding long-term outcome data are needed to address this clinical question.
IntroductionEndometrial hyperplasia is a precancerous lesion of the endometrium, commonly presenting with uterine bleeding. If managed expectantly, it frequently progresses to endometrial carcinoma, rates of which are increasing dramatically worldwide. However, the established treatment for endometrial hyperplasia (progestogens) involves multiple side effects and leaves the risk of recurrence. Metformin is the most commonly used oral hypoglycaemic agent in type 2 diabetes mellitus. It has also been linked to the reversal of endometrial hyperplasia and may therefore contribute to decreasing the prevalence of endometrial carcinoma without the fertility and side effect consequences of current therapies. However, the efficacy and safety of metformin being used for this therapeutic target is unclear and, therefore, this systematic review will aim to determine this.Methods and analysisWe will search the following trials and databases with no language restrictions: Cochrane Gynaecology and Fertility Specialised Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; EBSCO Cumulative Index to Nursing and Allied Health Literature; PubMed; Google Scholar; ClinicalTrials.gov; the WHO International Trials Registry Platform portal; OpenGrey and the Latin American and Caribbean Health Sciences Literature (LILACS). We will include randomised controlled trials (RCTs) of use of metformin compared with a placebo or no treatment, conventional medical treatment (eg, progestogens) or any other active intervention. Two review authors will independently assess the trial eligibility, risk of bias and extract appropriate data points. Trial authors will be contacted for additional data. The primary review outcome is the regression of endometrial hyperplasia histology towards normal histology. Secondary outcomes include hysterectomy rate; abnormal uterine bleeding; quality of life scores and adverse reactions to treatments.Ethics and disseminationDissemination of the completed review will be through the Cochrane Library as well as through presenting the results at appropriate conferences.
Early-onset Alzheimer’s disease (EOAD) can be familial (FAD) or sporadic (sEOAD); both have a disease onset ≤ 65 years of age. 451 sEOAD samples were screened for known causative mutations in exon 16 and 17 of the Amyloid Precursor Protein gene (APP). Four samples were shown to be heterozygous for one of three known causative mutations: p.A713T, p.V717I and p.V717G, this highlights the importance of screening EOAD patients for causative mutations. Additionally, we document an intronic 6 base pair (bp) deletion located 83 bp downstream of exon 17 (rs367709245, IVS17 83-88delAAGTAT), which has a non-significantly increased minor allele frequency in our sEOAD cohort (0.006) compared to LOAD (0.002) and controls (0.002). To assess the effect of the 6 bp deletion on splicing, COS-7 and BE(2)-C cells were transfected with a minigene vector encompassing exon 17. There was no change in splicing of exon 17 from constructs containing either wild type or deletion inserts. Sequencing of cDNA generated from cerebellum and temporal cortex of a patient harbouring the deletion found no evidence of transcripts with exon 17 removed.
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