Relationship between the polymorphism in exon 5 of BACE1 gene and Alzheimer's disease

Somatic Mutations and Alzheimer’s Disease

Alzheimer’s disease (AD) represents a global health challenge, with an estimated 55 million people suffering from the non-curable disease across the world. While amyloid-β plaques and tau neurofibrillary tangles in the brain define AD proteinopathy, it has become evident that diverse coding and non-coding regions of the genome may significantly contribute to AD neurodegeneration. The diversity of factors associated with AD pathogenesis, coupled with age-associated damage, suggests that a series of triggering events may be required to initiate AD. Since somatic mutations accumulate with aging, and aging is a major risk factor for AD, there is a great potential for somatic mutational events to drive disease. Indeed, recent data from the Gozes team/laboratories as well as other leading laboratories correlated the accumulation of somatic brain mutations with the progression of tauopathy. In this review, we lay the current perspectives on the principal genetic factors associated with AD and the potential causes, highlighting the contribution of somatic mutations to the pathogenesis of late onset Alzheimer’s disease. The roles that artificial intelligence and big data can play in accelerating the progress of causal somatic mutation markers/biomarkers identification, and the associated drug discovery/repurposing, have been highlighted for future AD and other neurodegenerative studies, with the aim to bring hope for the vulnerable aging population.

Association between the polymorphisms of CALM1 gene and osteoarthritis risk: a meta-analysis based on observational studies

The existing studies on the association between polymorphisms of Calmodulin 1 (CALM1) gene and the risk of osteoarthritis (OA, a complex multifactorial disease and a major degenerative form of arthritis) in different populations have yielded conflicting findings. Therefore, we conducted a meta-analysis by systematically searching PubMed, Embase, Medline, Cochrane Library and Google Scholar, and assessing this association by calculating pooled odds ratios with 95% confidence intervals. Subgroup analyses stratified by ethnicity, OA type, and genotype were also conducted. Six studies (2752 cases and 3259 controls) involving six single nucleotide polymorphisms were included. Our data suggested that the T allele and genotype TT of the rs12885713 polymorphism, and the C allele of the rs2300496 polymorphism in the CALM1 gene all increased the risk of OA. The pooled results revealed no significant association between the CALM1 rs3213718 polymorphism and the risk of OA. Stratification analyses by ethnicity and OA type showed that the rs12885713 polymorphism increased the risk of OA among Asians and in knee OA, respectively. In conclusion, the rs12885713 and rs2300496 polymorphisms of the CALM1 gene may both increase the risk of OA. Owing to the limitations of the present study, this finding should be further confirmed in future well-designed studies.

Lack of association between MTHFR A1298C variant and Alzheimer's disease: evidence from a systematic review and cumulative meta-analysis

OBJECTIVES

Previous studies have investigated the association between MTHFR A1298C (rs1801131) polymorphism and susceptibility to Alzheimer's disease (AD). Nevertheless, an ultimate conclusion remains obscure. We then executed this meta-analysis to estimate this association more precisely.

METHODS

Related studies were systematically searched on PubMed, Embase, China National Knowledge Infrastructure, Google scholar, and AlzGene databases. The association was evaluated by reviewing the odds ratios (ORs) with corresponding 95% confidence intervals (CIs). Publication bias, sensitivity analysis, and cumulative meta-analysis were performed to help draw a more definite conclusion.

RESULTS

Ten eligible studies were finally enrolled in this meta-analysis. Lack of association between MTHFR A1298C polymorphism and AD risk was observed in five genetic models (allelic: OR = 1.17, 95% CI: 0.88-1.56; homozygous: OR = 1.15, 95% CI: 0.87-1.53; heterozygous: OR = 1.19, 95% CI: 0.76-1.86; dominant: OR = 1.23, 95% CI: 0.81-1.87; recessive: OR = 1.16, 95% CI: 0.89-1.52). The result of cumulative meta-analysis sorted by publication year was also detected a dynamic tendency of no correlation between MTHFR A1298C polymorphism and AD.

CONCLUSION

This meta-analysis reveals that MTHFR A1298C polymorphism may not be associated with AD risk.