Roemer, Shanu F.

Abstract Genetic studies have significantly advanced our understanding of tauopathies, yet the genetic aetiology of Pick’s disease, a rare 3-Repeat tauopathy, remains unclear. The MAPT p.A152T variant has been identified as a risk factor for Alzheimer’s disease and progressive supranuclear palsy, but its role in Pick’s disease is unknown. In this study, we examined the prevalence of MAPT p.A152T in the largest series of neuropathologically confirmed Pick’s disease cases to date (n = 401). Through genotyping, we identified a single mutation carrier in the Pick’s disease cohort (minor allele frequency = 0.12%). We previously reported MAPT p.A152T at a 0.20% frequency in healthy controls (n = 2456), suggesting that it does not associate with 3-Repeat tauopathy risk. To further investigate the effect of the variant on MAPT transcript expression, we used bulk RNA sequencing in Alzheimer’s disease and progressive supranuclear palsy A152T mutation carriers. We did not detect significant differences in 4-Repeat tau levels, though preliminary trends may indicate more nuanced effects that need to be examined with long-read sequencing in a larger series. Overall, our study suggests that MAPT p.A152T does not increase Pick’s disease risk and may instead be linked to 4-Repeat or mixed tau pathologies, warranting further functional investigation.

Importance Tofersen is a disease-modifying antisense oligonucleotide therapeutic for people living with SOD1 –amyotrophic lateral sclerosis ( SOD1 -ALS). Autopsy tissue donors have provided the first opportunity to study the distribution of intrathecally administered tofersen in human central nervous system tissues. Objectives To determine the tissue distribution of tofersen and to provide the first estimates of SOD1 reduction in human somatic motor systems tissues. Design, Setting, and Participants This was a cross-sectional autopsy tissue case series conducted between 2018 and 2026. Autopsies were performed at 3 US academic medical institutions. Tissue samples from 8 deceased patients who lived with SOD1 -ALS, participated in tofersen clinical trials (ClinicalTrials.gov Identifiers NCT02623699 [An Efficacy, Safety, Tolerability, Pharmacokinetics and Pharmacodynamics Study of BIIB067 (Tofersen) in Adults With Inherited Amyotrophic Lateral Sclerosis (ALS)] and NCT03070119 [Long-Term Evaluation of BIIB067 (Tofersen)]) or the Expanded Access Program, and whose families authorized autopsies were eligible for this study. All autopsy tissue donors known at the time of this study were included (none were excluded). Analyses were conducted between August 2020 and January 2026. Exposures Participants received multiple intrathecal 20- to 100-mg tofersen doses. Main Outcomes and Measures Tofersen tissue concentrations were measured using hybridization enzyme-linked immunosorbent assay (ELISA). SOD1 messenger RNA (mRNA) and protein reduction estimates, defined as percentage SOD1 levels in this study’s recently treated autopsy tissue donors compared to a cohort of samples from tofersen-naive SOD1 -ALS autopsy tissue donors, were measured using quantitative reverse transcription polymerase chain reaction (PCR) and ELISA. Histological localization of tofersen and SOD1 transcripts were studied using immunohistochemistry and in situ hybridization assays. Results In 8 tofersen-treated autopsy tissue donors (5 male and 3 female donors; age range, 42-66 years), spinal cord and motor cortical tissue tofersen concentrations strongly correlated with predictions based on individual dosing histories and a preclinical pharmacokinetic model. For 3 recently treated autopsy tissue donors, reductions in lumbar spinal cord tissue SOD1 mRNA and protein levels ranged from 45% to 84% despite not having been administered 1 to 2 scheduled doses before autopsy. Residual somatic motor neurons demonstrated tofersen transduction and low SOD1 mRNA probe hybridization. Misfolded SOD1 protein inclusions were detected in residual motor neurons of tofersen-naive SOD1- ALS tissue donor controls and tofersen-treated tissue donors. Meningeal and perivascular lymphocytic immune responses were observed in 5 recently treated tissue donors but were not apparent in tissue donors with remote final tofersen doses. Conclusions and Relevance This case series presents the first emerging autopsy tissue data confirming the predicted distribution of tofersen and robust SOD1 protein reduction in human somatic motor systems tissues.

Abstract Background Colony stimulating factor 1 receptor–related disorder (CSF1R‐RD) is a rare, rapidly progressive neurodegenerative disease with significant clinical heterogeneity. Apolipoprotein E (ApoE) polymorphism, known to modulate microglial function and influence neurodegeneration, may act as a genetic modifier in CSF1R‐RD. Objectives The objectives were to evaluate the distribution of ApoE alleles in CSF1R‐RD and assess their association with clinical and neuropathological features. Methods ApoE genotyping was performed in 55 individuals with CSF1R‐RD. Clinical data from 25 deceased patients were analyzed based on ApoE genotype. Neuropathological evaluation was conducted on brain tissue from 14 patients, with semiquantitative scoring of white matter pathology and microglial burden. Statistical comparisons were made between carriers and noncarriers of the ApoE4 allele. Results ApoE allele frequencies in CSF1R‐RD mirrored those of the general population (ε2: 7.3%, ε3: 79.1%, ε4: 13.6%). However, ApoE4 carriers exhibited significantly earlier symptom onset (median: 37.9 vs. 50.3 years, p = 0.0123) and death (median: 41.1 vs. 55.2 years, p = 0.0072). Neuropathological analysis revealed more severe white matter involvement and reduced microglial preservation in ApoE4 carriers ( p = 0.034). Conclusions Although ApoE allele distribution does not differ from the general population, the presence of the ApoE4 allele may influence the clinical trajectory and white matter pathology in CSF1R‐RD. These findings suggest that ApoE polymorphism is a potential modifier of disease course and should be considered in therapeutic planning and future research. © 2026 International Parkinson and Movement Disorder Society.

Abstract Pick’s disease (PiD) is a rare cause of sporadic frontotemporal dementia, neuropathologically defined by the presence of Pick bodies consisting of aggregates of 3-repeat tau. Given the genetic aetiology of PiD remains unresolved, we assembled the Pick’s disease International Consortium (PIC) to identify susceptibility loci through a genome-wide association study (GWAS). A GWAS was conducted in 294 autopsy confirmed PiD cases and 1,055 controls. Lead variants were annotated using the Functional Mapping and Annotation of GWAS (FUMA) platform, followed by co-localisation analyses using the METABRAIN dataset and statistical finemapping using FINEMAP and SuSiE. After exclusion of 3 cases of MAPT mutations, no variants were associated with risk of PiD at genome-wide significance ( p < 5 × 10 -8 ). The strongest association was on chromosome 4 (4p13, lead SNP rs112161979, OR = 7.53, 95% Confidence Interval (CI) = 3.62-15.65, p = 6.37 × 10 -8 ) followed by chromosome 11 (11p15.4, lead SNP rs66481907, OR = 2.10, 95% CI = 1.54-2.84, p = 1.83 × 10 -6 ). rs112161979 is an intronic SNP in the KCDT8 gene, encoding a potassium channel tetramerization domain that acts as an auxiliary subunit for GABA B receptors, whilst rs66481907 is an intronic SNP in TRIM22 , encoding an E3 ubiquitin-protein ligase. Our GWAS provides the first evidence of possible genetic risk for PiD that implicate the modulation of GABA B receptor signalling and inflammation, in disease pathogenesis. Replication of these findings will be important, but our results suggest that, if present, the genetic risk of PiD beyond MAPT mutations is low.

Pick’s disease (PiD) is a rare neurodegenerative disorder defined by dementia, frontotemporal lobe atrophy, and 3-repeat tau inclusions. To elucidate PiD pathobiology, we performed the first bulk transcriptomics study on PiD using short- and long-read sequencing on the parietal cortex of 28 PiD and 15 control samples. We identified several significantly differentially expressed genes, with CCL2 displaying the strongest association with 3-repeat tau pathology and increased burden in PiD compared to those in 4-repeat tau progressive supranuclear palsy (PSP) cases. Investigation of co-expressed genes and pathways suggested the involvement of mRNA processing, mitochondrial function, and immune processes in disease pathobiology. Long-read RNA sequencing on a subset of samples (eight PiD and four control) proposed novel, potentially disease-associated transcripts for AZGP1 , CD44 , HSD11B2 , and WIF1 , predicted to result in truncated proteins. In conclusion, we observed transcriptomic changes in the parietal cortex of patients with PiD that may inform into clinically relevant biomarkers and therapeutic strategies.