The genetics of late-onset Alzheimer's disease (LOAD) has taken impressive steps forwards in the last few years. To date, more than six-hundred genes have been linked to the disorder. However, only a minority of them are supported by a sufficient level of evidence. This review focused on such genes and analyzed shared biological pathways. Genetic markers were selected from a web-based collection (Alzgene). For each SNP in the database, it was possible to perform a meta-analysis. The quality of studies was assessed using criteria such as size of research samples, heterogeneity across studies, and protection from publication bias. This produced a list of 15 top-rated genes: APOE, CLU, PICALM, EXOC3L2, BIN1, CR1, SORL1, TNK1, IL8, LDLR, CST3, CHRNB2, SORCS1, TNF, and CCR2. A systematic analysis of gene ontology terms associated with each marker showed that most genes were implicated in cholesterol metabolism, intracellular transport of beta-amyloid precursor, and autophagy of damaged organelles. Moreover, the impact of these genes on complement cascade and cytokine production highlights the role of inflammatory response in AD pathogenesis. Gene-gene and gene-environment interactions are prominent issues in AD genetics, but they are not specifically featured in the Alzgene database.
Notwithstanding some caveats (exclusion of gene-gene and gene-environment interactions; simple 5-HTTLPR architecture), this simulation is favourable to incorporate pharmacogenetic test in antidepressant treatment.
Introduction: Irritable mood (IM) and subthreshold hypomanic symptoms are reported in half and two-fifths of major depressed subjects respectively, but their clinical and prognostic meanings remain unclear. The aim of this study was to test the clinical usefulness of 2 specifiers in DSM-IV major depressive disorder (MDD): IM occurring during an index episode (IM+) and lifetime episodes of elated mood or IM with at least 2 concurrent hypomanic symptoms (subthreshold hypomanic episodes [SHEs]). Method: We included 482 outpatients with MDD participating in the Combining Medications to Enhance Depression Outcome study (mean age 43.14 ± 12.46 years, 144 males – 30%). The main aim of the original study was to test whether 2 different medications when given in combination as the first treatment step, compared to 1 medication, would improve antidepressant response. Results: IM + subjects (N = 349; 70%) were younger and more often females, with a more severe depression, a more marked social impairment, and more psychiatric comorbidities. The IM + group was also characterized by higher levels of suicidal ideation and more cases of emotional abuse. The combination of IM+ and SHEs was associated with an even more severe clinical picture. Limitations include the post hoc method, incomplete assessment of bipolar validators (e.g., family history of bipolar illness), personality disorders and suicide attempts. Conclusions: The presence of IM and SHEs in MDD correlate with an overall more severe clinical condition.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.