Deleterious ABCA7 mutations and transcript rescue mechanisms in early onset Alzheimer’s disease

Abstract: Premature termination codon (PTC) mutations in the ATP-Binding Cassette, Sub-Family A, Member 7 gene (ABCA7) have recently been identified as intermediate-to-high penetrant risk factor for late-onset Alzheimer's disease (LOAD). High variability, however, is observed in downstream ABCA7 mRNA and protein expression, disease penetrance, and onset age, indicative of unknown modifying factors. Here, we investigated the prevalence and disease penetrance of ABCA7 PTC mutations in a large early onset AD (EOAD)-control cohort, and examined the effect on transcript level with comprehensive third-generation long-read sequencing. We characterized the ABCA7 coding sequence with next-generation sequencing in 928 EOAD patients and 980 matched control individuals. With MetaSKAT rare variant association analysis, we observed a fivefold enrichment (p = 0.0004) of PTC mutations in EOAD patients (3%) versus controls (0.6%). Ten novel PTC mutations were only observed in patients, and PTC mutation carriers in general had an increased familial AD load. In addition, we observed nominal risk reducing trends for three common coding variants. Seven PTC mutations were further analyzed using targeted long-read cDNA sequencing on an Oxford Nanopore MinION platform. PTC-containing transcripts for each investigated PTC mutation were observed at varying proportion (5-41% of the total read count), implying incomplete nonsense-mediated mRNA decay (NMD). Furthermore, we distinguished and phased several previously unknown alternative splicing events (up to 30% of transcripts). In conjunction with PTC mutations, several of these novel ABCA7 isoforms have the potential to rescue deleterious PTC effects. In conclusion, ABCA7 PTC mutations play a substantial role in EOAD, warranting genetic screening of ABCA7 in genetically unexplained patients. Long-read cDNA sequencing revealed both varying degrees of NMD and transcript-modifying events, which may influence ABCA7 dosage, disease severity, and may create opportunities for therapeutic interventions in AD

The Limits of the European Union’s Transformative Power: Pathologies of Europeanization and Rule of Law Reform in Central and Eastern Europe

This thesis examines the impact of the European Union (EU) on the development of the rule of law in Central and Eastern Europe. The topic is addressed through a mixed methods study which consists of a quantitative comparative analysis of three country groups from Central and Eastern Europe (1. Central Europe and the Baltics, CEB; 2. South Eastern Europe, SEE; 3. Commonwealth of Independent States, CIS) and three qualitative case studies on Poland, Romania and Moldova. The empirical analysis is based on an innovative set of indicators and revealing insights from numerous qualitative interviews. The findings of the study suggest that the impact of the EU is differential, both healthy and pathological. While EU-driven judicial reforms increase judicial capacity and align domestic legislation with European and international standards (substantive legality), they do not improve and even lead to a deterioration of judicial impartiality and formal legality, resulting in several reform pathologies, such as instable, incoherent and non-enforced laws and in more politicized and incoherent judicial systems, which undermine the development of the rule of law. These pathological effects occur mostly in weak rule of law countries from SEE (Romania) and CIS (Moldova), in contrast to more healthy effects in advanced, strong rule of law countries from CEB (Poland). The dissimilar development in the rule of law across countries is explained in relation to the conduct of reforms. Successful reformers like Poland, which consolidate the rule of law, have strong and independent horizontal accountability institutions (e.g. Constitutional Court, Ombudsman, judiciary), which mitigate or alleviate reform pathologies and ensure that reforms are conducted in an accountable, gradual and non-politicized way. Unsuccessful reformers, like Romania and Moldova, lack these independent checks on reformers and thus fail to establish the rule of law. Based on the findings from the case studies an original typology of healthy and pathological reform paths is proposed, which draws on the logic of circular and cumulative causation and emphasizes the mutual reinforcement between domestic conditions and the reform approach of transnational coalitions. The proposed typology implies that EU conditionality is not transformative, but rather reinforces existing healthy and pathological reform paths, thus cementing the existing divergence in the rule of law across post-communist countries. This thesis further makes several policy recommendations to remedy the pathological impact of donor-driven reforms