Objective: The basis for clinical variation related to underlying progressive supranuclear palsy (PSP) pathology is unknown. We performed a genome-wide association study (GWAS) to identify genetic determinants of PSP phenotype.
Methods: Two independent pathological and clinically diagnosed PSP cohorts were genotyped and phenotyped to create Richardson syndrome (RS) and non-RS groups. We carried out separate logistic regression GWASs to compare RS and non-RS groups and then combined datasets to carry out a whole cohort analysis (RS = 367, non-RS = 130). We validated our findings in a third cohort by referring to data from 100 deeply phenotyped cases from a recent GWAS. We assessed the expression/coexpression patterns of our identified genes and used our data to carry out gene-based association testing.
Results: Our lead single nucleotide polymorphism (SNP), rs564309, showed an association signal in both cohorts, reaching genome-wide significance in our whole cohort analysis (odds ratio = 5.5, 95% confidence interval = 3.2-10.0, p = 1.7 × 10-9 ). rs564309 is an intronic variant of the tripartite motif-containing protein 11 (TRIM11) gene, a component of the ubiquitin proteasome system (UPS). In our third cohort, minor allele frequencies of surrogate SNPs in high linkage disequilibrium with rs564309 replicated our findings. Gene-based association testing confirmed an association signal at TRIM11. We found that TRIM11 is predominantly expressed neuronally, in the cerebellum and basal ganglia.
Interpretation: Our study suggests that the TRIM11 locus is a genetic modifier of PSP phenotype and potentially adds further evidence for the UPS having a key role in tau pathology, therefore representing a target for disease-modifying therapies. Ann Neurol 2018;84:485-496.
© 2018 The Authors. Annals of Neurology published by Wiley Periodicals, Inc. on behalf of American Neurological Association.