Acta Neuropathologica Communications

TDP-43 proteinopathy is a neuropathological hallmark of nearly all amyotrophic lateral sclerosis (ALS) and approximately half of frontotemporal dementia (FTD) cases. Nuclear loss of TDP-43 leads to widespread RNA misprocessing, such as the inclusion of cryptic exons that are no longer repressed by TDP-43. Notably, in-frame cryptic exons encode novel cryptic peptides that can be detected in biofluids, including that found in the HDGFL2 transcript. Here, we quantified HDGFL2 cryptic peptide and neurofilament light chain (NfL) in paired cerebrospinal fluid (CSF) and plasma samples from ALS and FTD patients. Cryptic HDGFL2 peptide was detected in the CSF of ALS patients, whereas no significant differences were observed between genetic and behavioral FTD subgroups. In contrast, NfL levels were elevated in both ALS and FTD, although this biomarker does not reflect TDP-43 pathology. Notably, NfL:HDGFL2 cryptic peptide ratio outperformed either marker alone in discriminating ALS and FTD cases from controls, achieving high specificity. Moreover, this ratio correlated with disease progression in ALS, suggesting added prognostic value. Collectively, our findings support the NfL:HDGFL2 cryptic peptide ratio as a promising fluid biomarker that integrates neurodegeneration with TDP-43 dysfunction, potentially improving diagnostic accuracy, disease stratification, and longitudinal monitoring in TDP-43-associated neurodegenerative disorders.

BackgroundChitinases, including chitotriosidase (CHIT1) and chitinase-3-like protein 1 (CHI3L1), are markers of neuroinflammation, a key process in amyotrophic lateral sclerosis (ALS). Tear fluid (TF) can be collected non-invasively and may represent a promising alternative to CSF or blood to study chitinases. MethodsTF was collected from 50 ALS patients and 50 control subjects using Schirmer strips. CHIT1 and CHI3L1 levels in TF, serum, and CSF were quantified using ELISA. Serum NfL was measured using SIMOA. The frequency of a 24 bp-duplication polymorphism in the CHIT1 gene influencing CHIT1 expression was assessed by PCR. ResultsNo group differences in the distribution of the CHIT1 polymorphism were detected. Carriers of the polymorphism in both ALS and controls showed lower CHIT1 levels in serum and TF. CHI3L1 levels in TF were higher in ALS patients compared to controls (p = 0.007), consistent with changes in CSF but not serum. In ALS, males showed higher TF CHIT1-values compared to females (p = 0.009). Combining TF chitinase values with serum NfL values improved discrimination between ALS and controls. ConclusionsChitinases are detectable in TF, and CHI3L1 levels recapitulate changes observed in CSF, highlighting its potential for non-invasive longitudinal assessment. Furthermore, chitinase values in TF, together with serum NfL, may act complementary by capturing distinct aspects of the disease, neuroinflammation and axonal damage. These results suggest TF chitinases and serum NfL could complementarily contribute to the diagnosis and monitoring of the disease, and call for further evaluation of TF as a biomarker source in ALS.

An overlap syndrome of myositis and/or myocarditis associated with myasthenia gravis (MG) has emerged as a life-threatening immune-related adverse event (irAE) in cancer patients treated with immune checkpoint inhibitors (ICIs). This syndrome closely resembles a rare form of idiopathic inflammatory myopathy (IIM) seen in a subset of MG patients. In this systematic review, we searched PubMed for reports of concurrent MG and IIM as well as ICI-related overlap syndromes. By integrating clinical, serological, and pathological observations, we delineated a previously unrecognized clinicopathological subtype of myositis that overlaps with MG. This entity is defined by a strong association with striational antibodies (StrAbs) and frequent co- occurrence with thymoma as a paraneoplastic process, and we classify it as StrAb-associated myositis. The idiopathic and ICI-induced forms share similar, though not identical, clinical, serological, and histopathological characteristics. We found that AChR antibody positivity, independent of established clinical risk factors such as respiratory or cardiac involvement, predicted more severe ICI-myotoxicity. Together with supporting evidence, our findings suggest a pathogenic model in which thymoma-driven cytotoxic T-cell responses trigger secondary AChR autoimmunity. These results highlight the potential utility of StrAbs and anti-AChR antibodies as practical biomarkers for diagnosis, risk stratification, and early intervention in patients at risk for severe neuromuscular irAEs.

BackgroundIsocitrate dehydrogenase wildtype (IDHwt) histologic grade 2 adult diffuse gliomas represent a highly heterogeneous entity, and the effects of postoperative adjuvant temozolomide (TMZ) therapy, as well as the predictive value of chemotherapy-related biomarker O6-methylguanine-DNA methyltransferase promoter (MGMT-p) methylation, remain to be further investigated. MethodsA Discovery dataset, comprising 108 IDHwt histologic grade 2 gliomas obtained from three public resources, was constructed to investigate the impact of TMZ on patient survival. Furthermore, an independent Validation dataset, consisting of 123 IDHwt grade 2 gliomas, was created to validate the effect of TMZ on patient survival. Kaplan-Meier overall survival (OS) analyses and Cox proportional hazard models were used. ResultsMultivariable analysis in the validation dataset demonstrated that temozolomide (TMZ) chemotherapy was an adverse independent prognostic factor for survival in patients with histologic grade 2 IDH-wildtype (IDHwt) gliomas (HR = 2.19, P = 0.033). Subgroup analyses further revealed that the detrimental effect of TMZ was mainly confined to MGMT-p unmethylated tumors (Discovery cohort: TMZ vs noTMZ, median overall survival [OS]: 37.0 vs 130.0 months, log-rank P = 0.005, HR = 1.89; Validation cohort: TMZ vs noTMZ, median OS: 34.4 vs >120 months, log-rank P = 0.004, HR = 3.39). Moreover, in the validation cohort, TMZ therapy remained associated with significantly poorer survival in the NEC (Not Elsewhere Classified) subgroup (TMZ vs noTMZ, median OS: 73 vs >120 months, P = 0.017), while in molecular GBMs it did not reach statistical significance but still showed a trend toward worse survival (TMZ vs noTMZ, median OS: 20 vs 30 months, P = 0.37). By comparing multi-omics differences between patient groups, we observed that MMR-related genes were specifically downregulated in IDHwt grade 2 gliomas at both the single-cell and bulk transcriptomic levels. DiscussionThe therapeutic benefit of TMZ in IDHwt histologic grade 2 gliomas appears to be limited, with even a potential adverse impact on survival. Therefore, postoperative use of TMZ as a recommended chemotherapy should be approached with caution in these patients, particularly in cases with unmethylated MGMT-p, where alternative treatment strategies are warranted. High MGMT expression and specific downregulation of MMR-related genes may represent key factors underlying the limited efficacy of TMZ in IDHwt, MGMT-p unmethylation grade 2 gliomas. Level of evidenceIII.

ObjectiveDuchenne muscular dystrophy (DMD) is a progressive neuromuscular disorder for which monitoring biomarkers are urgently needed. We aimed to evaluate whether proteins in serum can accurately monitor patients function within the duration of a clinical trial. MethodsIn this study, we evaluated longitudinal serum proteins of DMD patients participating to the FOR-DMD clinical trial, comparing daily and intermittent corticosteroid regimens in boys aged 4-8 years at baseline. Using the aptamer-based protein platform SomaScan, we profiled 1500 proteins. Associations between protein levels and motor function outcomes, such as Rise from the Floor Velocity (RFV), 10-Meter Run/Walk Velocity (10MRWV), and North Star Ambulatory Assessment (NSAA), were assessed using linear mixed models. In particular, we explored whether patients with higher protein levels also tended to have better functional scores (across-patients analysis), and whether changes in protein levels within the same patient over time were linked to changes in their functional performance (within-patient analysis). Finally, penalized (Lasso) mixed models were applied to evaluate the predictive function of the proteins. The prediction accuracy of the models (evaluated by optimism-corrected Root Mean Squared Error) was compared to that of a simpler model with only age and treatment as predictors. ResultsAcross-patients and within-patient analyses revealed consistent associations with three functional tests for a subset of proteins, notably RGMA, ART3, ANTXR2, and CFB. Multivariate models incorporating the proteins significantly associated with at least two tests, improved prediction accuracy for NSAA and RFV by 21% and 8%, respectively. These models also revealed a subset of proteins that were consistently selected. Quantification of CFB, RGMA, ANTXR2, SERPINF1 and ATP5PF using SomaScan showed strong agreement with measurements obtained using orthogonal methods such as ELISA, MRM-MS and an in-house developed bead-based sandwich immunoassay. DiscussionThese findings support the utility of serum protein signatures as objective, quantitative tools for monitoring disease progression and treatment response in DMD during clinical visits and clinical trials.

In LGMDR1-Calpain-3 related, as in all muscular dystrophies, clinical trial monitoring remains a challenge due to the lack of reliable biomarkers. This study assessed IL-32 concentrations in both serum and urine, uncovering a marked increase in patients compared to healthy controls. Serum IL-32 levels were especially elevated in young adults, suggesting a possible link to the early and more active phases of disease onset. Meanwhile, urinary IL-32 levels showed consistent elevation across all age groups, reinforcing its promise as a stable, non-invasive biomarker. These findings support the potential of IL-32 in monitoring disease progression and therapeutic response in clinical trials, and underscore its potential involvement in LGMDR1.

Advances in transcriptomics have transformed our understanding of amyotrophic lateral sclerosis (ALS), a progressive neurodegenerative disease, revealing disrupted gene expression profiles and highlighting the multi-system biology of ALS. Despite major advances, transcriptomic studies have only begun to capture the complexity and the molecular hierarchy of transcriptomic alterations in ALS. To resolve and characterize the transcriptome in ALS, we performed a comprehensive reanalysis of bulk RNA sequencing from the New York Genome Center ALS Consortium cohort across five post-mortem tissues including motor and frontal cortex, cervical and lumbar spinal cord, and cerebellum. By deploying dual analytical pipelines - one reference-based to model canonical events and one de novo to detect transcript structural novelties - we disentangled the quantitative and qualitative architectures of ALS. Our reference-based analysis revealed that ALS transcriptome is defined primarily by splicing failure rather than changes in gene expression. Aberrant splicing events, particularly intron retention, outnumbered differentially expressed genes by an order of magnitude. This widespread loss of fidelity disproportionately affected RNA-binding proteins, suggesting a collapse in their autoregulatory feedback loops. Deconvolution of these signals identified distinct cellular vulnerabilities: transcriptional disruptions were enriched in glial cells in sporadic cases but in neuronal cells in C9ORF72-positive cases. Furthermore, we observed sex-specific dysregulation, with male patients exhibiting greater disruption in guanosine triphosphatase signaling and ciliary organization pathways. In parallel, our de novo analysis uncovered a significant burden of disease-specific gene fusions that were absent in controls. Whole-genome sequencing of the same individuals, together with a larger reference population confirmed that disease-specific fusions do not arise from genomic structural variants, indicating a transcriptional rather than genomic origin. Investigation into the mechanism of these RNA-based fusions revealed a critical deviation in splice site definition: while canonical splice junctions exhibit a high density of binding motifs for polyA-binding or 3-cleaveage proteins approximately 50 base pairs upstream of the splice donor site (left junction), ALS-specific fusion junctions displayed a dramatic depletion of these motifs in the same region. Functionally, the presence of these sparse disease-specific fusions was strongly correlated with severe splicing outliers in genes governing guanosine triphosphatase activity, converging with the tissue- and male-specific defects identified in our reference-based analysis. Altogether, our results delineated a transcriptome characterized by aberrant splicing with tissue-and sex-specific changes and identified structural-variant-independent RNA fusions as candidate disease modifiers that may amplify pathology. This integrated view provides a mechanistic scaffold for splicing-centered and RNA-structural therapeutic strategies for ALS.

T-cell lymphomas are often histologically indistinguishable from benign T-cell infiltrates. Clonality testing is frequently required for diagnosis. It lacks the spatial context and is slow and expensive, relying on complex, multiplexed PCR reactions, interpreted by experienced scientists or pathologists. We previously published details of a pair of highly specific monoclonal antibodies against the two alternatively used, but very similar, T-cell receptor {beta} constant regions, TCR{beta}1 and TCR{beta}2. We demonstrated the feasibility of immunohistochemical detection of TCR{beta}1 and TCR{beta}2 in formalin-fixed, paraffin-embedded (FFPE) tissue as a novel diagnostic strategy for T-cell lymphomas. Here we validate an improved pairing of TCR{beta}1/2 rabbit monoclonal antibodies, and demonstrate their utility for single and double immunostaining, including with a chimeric mouse anti-TCR{beta}2 antibody. Finally, we show that this staining is amenable to automated cell counting, permitting accurate calculation of the TCR{beta}2:TCR{beta}1 ratio.

While 18F-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) is an established biomarker in amyotrophic lateral sclerosis (ALS), the metabolic correlates of motor neuron disease motor variants remain poorly defined. This is why we investigated patterns of cerebral glucose metabolism across the spectrum of motor neuron disorders (MND), including progressive muscular atrophy (PMA), primary lateral sclerosis (PLS) and amyotrophic lateral sclerosis (ALS). We retrospectively included 18 PMA, 25 PLS and 43 matched non-hereditary ALS patients according to most recent diagnostic criteria. FDG-PET imaging revealed similar widespread hypometabolism in PMA, as in ALS, whereas PLS showed a more focal motor cortical pattern of hypometabolism. Despite clinical differences between MND subtypes, PMA and ALS showed similar FDG-PET metabolic patterns, whereas PLS exhibited a more restricted cortical signature in this retrospective study.

1Amyotrophic lateral sclerosis (ALS) is highly heritable, yet the vast majority of cases lack an identifiable genetic cause and clinical progression remains largely unpredictable. To connect noncoding and rare genetic variation to disease phenotypes in a relevant cell type, we generated a multi-omic quantitative trait locus (QTL) atlas from 594 induced-pluripotent-stem-cell-derived human motor neuron lines (522 ALS patients, 72 controls). By mapping cis-QTLs for chromatin accessibility, splicing and gene expression from whole-genome sequencing, we identify common and rare variants on the wild-type C9orf72 allele that form regulatory haplotypes. These haplotypes influence C9orf72 expression levels in motor neurons and stratify C9-ALS patients into four subgroups; using clinical disease duration data and longitudinal ALSFRS-R scores, we show that these subgroups exhibit different survival trajectories, indicating that wild-type C9orf72 expression acts as a genetic modifier of disease duration. Beyond the C9orf72 locus, we detect ultra-rare intronic variants that create cryptic exons and structural and nonsense variants in established ALS genes, providing likely genetic explanations for disease in additional patients who previously lacked a molecular diagnosis. Our results show that QTL mapping in patient-derived motor neurons can reveal regulatory modifiers of progression and hidden pathogenic events in ALS, providing a framework for genetically informed risk attribution and patient stratification in complex neurological diseases.

Meningiomas are the most common primary brain tumors and, despite their benign reputation, often behave aggressively. Meningiomas are morphologically heterogeneous, yet the full significance of their histologic diversity is unclear. This is in large part because many features are not readily quantifiable by traditional observer-based light microscopy. Molecular testing improves prognostic stratification, but is not universally accessible. We therefore sought to determine whether an artificial intelligence (AI)-trained program could predict specific genomic and epigenomic patterns in meningiomas, and whether it could extract more prognostic information out of standard hematoxylin and eosin (H&E) histopathology than the current WHO classification. To do this, we developed Morphologic Set Enrichment (MSE), an interpretable computational pathology framework that quantifies statistical enrichment of morphologic patterns, cells, and tissue architecture from H&E whole-slide images. The MSE meningioma histology program was able to accurately predict DNA methylation subtypes and concurrent chromosome 1p/22q losses, in the process identifying specific morphologic patterns associated with key genomic and epigenomic alterations. It also added prognostic value independent of standard clinical and pathological variables. These results demonstrate that AI-based quantitative morphologic profiling can capture clinically and biologically relevant information that redefines risk stratification for meningiomas, incorporating histological information not included in existing grading schemes.

Objective-synucleinopathies are clinically and biologically heterogeneous disorders lacking reliable biomarkers to assist with early diagnosis, disease progression, patient stratification, and therapeutic targeting. Genetic variation is known to impact biomarker levels, influencing their utility and interpretation in research and clinical settings. We aimed to identify common genetic modulators of biomarker levels implicated in -synucleinopathy pathogenesis. MethodsGenome-wide association studies (GWASs) were conducted on 63 CSF, plasma, and urine biomarkers in 581 individuals from the Parkinsons Progression Markers Initiative (PPMI). Analyses were adjusted for age, sex, disease status, and principal components. PD- and DLB-risk loci associations were separately assessed for each GWAS. ResultsWe confirm strong associations between urine bis(monoacylglycerol)phosphate (BMP) isoforms and the variants LRRK2 p.G2019S and GBA1 p.N370S, while providing support for BMPs use as a LRRK2-PD biomarker. CSF A{beta} was significantly associated with an APOE {varepsilon}4 allele, reinforcing its central role in amyloid regulation. Novel associations were detected between CSF ceramide isoforms the MCF2L2 and GMNN loci, and between CSF tau and the TP63 locus. Multiple PD risk loci, including MAPT, SIPA1L2, MCCC1, and RAB29, were associated with lysosomal lipid biomarkers, highlighting pathway-level convergence. InterpretationThe present study reveals established and novel genetic modulators of potential -synucleinopathy biomarkers, demonstrating that genetic background significantly shapes biomarker levels. These genetic influences should be accounted for when conducting biomarker-based research, clinical trials, or therapeutic development to ensure accurate interpretation and improve their translational relevance.

Protocadherin-12 (PCDH12), a cell-adhesion protein belonging to the non-clustered protocadherin family, plays a crucial role in the establishment and regulation of neuronal connections and communication. Bi-allelic loss-of-function (LoF) variants in the PCDH12 gene have been associated with several neurodevelopmental disorders (NDDs) such as diencephalic-mesencephalic junction dysplasia (DMJD) syndrome, cerebral palsy, and cerebellar ataxia, often accompanied by ocular abnormalities. However, genotypes exhibit variable expressivity. Affected individuals sharing the same PCDH12 variant presenting differing phenotypic severities have posed major challenges towards identification of the underlying pathogenic mechanisms. Here, we report three affected individuals from two families, each harbouring non-truncating pathogenic missense variants in PCDH12. The patients are compound heterozygous, with each individual carrying one extracellular [c.1742T>G (p.Val581Gly) and c.1861_2del/insCA (p.Ile621His)] and one intracellular variant [c.3370C>T (p.Arg1124Cys) and c.3445G>A (p.Asp1149Asn] on each allele. The children present with a range of phenotypes similar to those associated with LoF variants. One child exhibited microcephaly and seizures, while the two siblings displayed developmental delays and severe behavioral disorders. All three children experienced some degree of visual impairment. The missense variants provided new insights into the neurodevelopmental consequences of compromised PCDH12 function by distinguishing the specific consequences associated with dysfunction in the extracellular versus intracellular domains of PCDH12. All identified missense variants are predicted to be deleterious and destabilizing. The expression of PCDH12 in HEK293T and HeLa cells demonstrated that PCDH12 is expressed effectively, regardless of the presence of missense variants. However, the extracellular variants p.Val581Gly and p.Ile621His compromised the stability of PCDH12's homophilic adhesion. Additionally, we found evidence of an interaction between PCDH12 and the extracellular domain of the epilepsy-associated PCDH19 protein. PCDH12 extracellular missense variants also negatively impact this interaction. Our study provides evidence that PCDH12 mediates both homophilic and heterophilic interactions. Our findings also highlight the importance of stable PCDH12-mediated adhesion, emphasizing the need to further study the functional consequences of PCDH12 missense variants on brain and visual system development.

Background Whole-genome sequencing (WGS) has improved the diagnosis of rare genetic disorders, yet interpretation of non-coding variants that affect splicing remains challenging. In silico predictions alone are insufficient, and short-read RNA sequencing may fail to capture complex or low-abundance splicing events. Targeted amplicon-based long-read RNA sequencing (Amp-LRS) offers a cost-effective approach for functional validation of candidate splice-altering variants. Methods We applied Amp-LRS to five patients with neurological disorders (central nervous system, peripheral nervous system, or muscle) harbouring candidate non-coding variants predicted to alter splicing. RNA was extracted from fibroblasts or peripheral blood, and full-length transcript amplicons were sequenced using Oxford Nanopore Technologies. Nonsense-mediated decay (NMD) inhibition was performed on fibroblast cultures using cycloheximide. Results Amp-LRS validated all five candidate variants, including intronic and UTR variants in POLR3A, OPA1, PYROXD1, GDAP1, and SPG11. Aberrant splicing events included exon skipping, intron retention, cryptic splice site activation, and pseudoexon inclusion, often resulting in frameshifts and premature termination codons. For POLR3A and OPA1, multiple abnormal isoforms arose from single variants, highlighting the complexity of splicing disruption. Some pathogenic effects were detectable only in a minority of reads and variably enriched by NMD inhibition, consistent with being hypomorphic. The approach was successfully applied using accessible tissues and enabled multiplexed sequencing at low per-sample cost. Conclusions Amp-LRS is a sensitive, versatile, and cost-effective method for functional assessment of non-coding splice-altering variants identified by WGS. By enabling full-length transcript analysis from accessible tissues, this approach improves interpretation of variants of uncertain significance and could enhance molecular diagnosis in rare neurological diseases.

Leucine-rich repeat kinase 2 (LRRK2) variants are the most common cause of inherited Parkinsons disease (PD), and the hyperactivity of the LRRK2 variants represent a validated drug target for PD. The penetration of common LRRK2 variants is incomplete, underscoring the need for molecular biomarkers that predict disease onset and guide therapeutics development. Here, we analyzed large datasets of cerebrospinal fluid (CSF) and urinary proteomics from the Parkinsons Progression Markers Initiative (PPMI) and identified distinct lysosomal and immune protein signatures as potential biomarkers for LRRK2-linked PD (LRRK2 PD). Longitudinal analysis revealed that levels of specific lysosomal and immune proteins remained elevated in CSF during the prodromal phase but declined following clinical symptom onset. Furthermore, examination of multiple brain cell types from Lrrk2 mutant mice carrying disease variant (G2019S) showed heightened secretion of lysosomal proteins in microglia and astrocytes, but not neurons, supporting a glial origin and intrinsic LRRK2 mutant activity responsible for the elevated CSF lysosomal proteins. Furthermore, proteomics analysis of urine from humanized LRRK2G2019Stransgenic mice identified lysosome and glycosphingolipid protein signatures shared with human LRRK2 PD patients. Collectively, our integrated proteomics reveals dynamic changes of functional biofluid signatures for LRRK2 PD, which enables the determination of biomarkers for early disease onset. The humanized LRRK2G2019S mice provide a valuable platform for biomarker refinement and therapeutic development. One Sentence SummaryIntegrated human and mouse proteomic analyses identify dynamic lysosomal and immune biofluid signatures, possibly of glial origin, as functional biomarkers of LRRK2-linked Parkinsons disease progression, supported by a novel humanized LRRK2G2019S mouse model that recapitulates key urinary biomarker profiles.

Spinal muscular atrophy (SMA) is a severe neuromuscular disorder caused by reduced expression of the survival motor neuron (SMN) protein. In addition to affecting motor neuron survival, SMN deficiency impacts multisystem physiology and neurotransmission. Dopaminergic dysfunction has been reported in mouse models of SMA, leading to postural and locomotor impairments that improve upon treatment with L-DOPA and benserazide. However, whether altered dopamine metabolism contributes to clinical symptoms in SMA patients remains unclear. To investigate this issue, we conducted a real-world observational study involving pediatric patients with SMA1, SMA2, and SMA3. We performed a longitudinal measurement of the main dopamine-related catabolites - 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) - in cerebrospinal fluid (CSF) samples collected at baseline and after five intrathecal doses of Nusinersen, an SMN-enhancing therapy. No significant differences were observed in CSF DOPAC and HVA levels across SMA types or following treatment, and no association emerged with SMN2 copy number. In contrast, lower baseline DOPAC levels were detected in SMA1 patients requiring gastrostomy and tracheostomy, and were associated with reduced improvement on the CHOP-INTEND scale. These findings suggest that reduced central dopaminergic turnover reflects disease progression in SMA1 and is associated with more severe clinical impairment and limited functional recovery.

BackgroundPATZ1 fusion-positive central nervous system (CNS) tumors frequently harbor MN1::PATZ1 fusions as driver mutations, provisionally classified as a rare DNA methylation class of low-grade neuroepithelial tumors. Radiographically, they resemble pilocytic astrocytomas with tumor and cystic components, but their supratentorial cortex location and higher recurrence rates are distinguishing features. An intermediate clinical course, despite focal high-grade histopathology, underscores the need for longitudinal molecular and immune analyses to refine classification and standard therapy. Case SummaryA female pediatric patient presented with neurological symptoms, including headache and right upper extremity weakness. MRI revealed a large cystic lesion in the left frontal lobe, leading to a differential diagnosis of low-grade glioma and ependymoma. Genomic analysis identified an MN1::PATZ1 fusion. The tumor recurred after gross total resection prompting a second resection. Transcriptomic and histopathologic assessments identified multiglial lineage, and high-grade features closely related to adult glioblastoma alongside pro-inflammatory activity in the primary tumor. The recurrent tumor showed reduced malignancy, and oligodendroglioma-like features. Increased MHC gene expression, immune checkpoint receptors (PDCD1, CTLA4, TIGIT,TIM3), T cell regulators (CXCR6), and elevated macrophage frequency, coupled with reduced PD-L1 in the recurrent tumor, suggest a complex anti-tumor immune response constrained by T cell dysregulation. This case, along with two other MN1::PATZ1 fusion-positive tumors, identifies a distinct transcriptomic subtype separate from circumscribed astrocytic glioma, highlighting upregulation of growth factor receptor pathways, like PI3K/AKT, and immune dysfunction linked to recurrence. ConclusionLongitudinal multi-omics analyses of recurrent MN1::PATZ1 fusion-positive CNS tumors revealed tumor maturation, immune dysfunction, and potential therapeutic targets. Introductory ParagraphPATZ1 fusion-positive central nervous system (CNS) tumors are rare, predominantly pediatric and frequently recurrent neoplasms provisionally classified as neuroepithelial tumors. Their pronounced histopathological and clinical heterogeneity, along with limited immunological characterization complicates their treatment standardization. We report a new case of an MN1::PATZ1 fusion-positive CNS tumor with recurrence, highlighting its radiographic similarities to low-to-intermediate grade pediatric glioma. Longitudinal multi-omics analyses of this case, along with additional MN1::PATZ1 fusion-positive CNS tumors, however, delineates a transcriptome subtype resembling adult high-grade glioma, with activated oncogenic and pro-inflammatory programs. The recurrent tumor exhibits features of decreased malignancy and enhanced glial differentiation, phenotypically shifting towards oligodendroglioma, suggesting tumor maturation. This was accompanied by increased antigen presentation programs, indicating immune engagement, while increased immune checkpoint expression and microglia/macrophage frequency indicate T cell exhaustion and immunomodulation, respectively. This longitudinal study highlights potential therapeutic strategies targeting both the tumor and its immune environment in MN1::PATZ1 fusion-positive CNS tumors.

Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative condition characterized by the presence of intranuclear inclusions in neuronal and visceral cells. Patients with NIID can present respiratory symptoms; however, data on pulmonary functions in NIID are lacking. This study investigated the respiratory conditions in NIID patients diagnosed with histopathological and genetic studies. We conducted two spirometries before and after administrating the bronchodilator in NIID patients with asthmatic histories or symptoms. We statistically compared pre- and post-measured values including forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and peak expiratory flow (PEF). Before two spirometries, we also measured fractional concentration of exhaled nitric oxide (FeNO), if possible. Of the 51finally enrolled patients, 17 (33.3%, 95% CI 20.8% to 47.9%) patients had asthmatic histories or symptoms, and 14 patients received two spirometries. After administrating the bronchodilator, FEV1 and PEF significantly increased by 150 mL (6.01%, p = 0.002) and 260 mL/s (6.72%, p = 0.017), respectively. The median (interquartile range) of FeNO measured in nine patients was 15 (10-21) ppb. Patients with NIID have airflow reversibility like asthma. Airway inflammation is less associated with this condition; thus, immunomodulators such as corticosteroid may not improve respiratory symptoms in NIID.

BackgroundBiomarkers of abnormal alpha-synuclein (asyn) that can be obtained with minimal invasiveness are needed. Promising data on dermal serine-129-phosphorylated alpha-synuclein (dermal-ps129-asyn) have emerged but accuracy for aggregated asyn in cerebrospinal fluid (CSF) has not been examined. ObjectiveDetermine sensitivity and specificity of dermal-ps129-asyn for neuronal asyn measured with cerebrospinal fluid asyn seed amplification assay (CSFasynSAA). MethodsCross-sectional observational study; 50 individuals with positive or negative CSFasynSAA underwent 3 skin biopsies for blinded assessment of phospho-serine-129 asyn in nerve terminals. Sensitivity and specificity versus CSFasynSAA were calculated. ResultsAmong 50 participants, 30/38 CSFasynSAA+ were dermal-ps129-asyn+; 6/12 CSFasynSAA-were dermal-ps129-asyn-, yielding sensitivity of 79% and specificity of 50%. ConclusionDermal-ps129-asyn has low specificity for CSF asyn SAA in this small sample. This precludes its use as a marker of CSF neuronal asyn aggregates. Future studies are needed to determine optimal methods to assess asyn aggregates in central and peripheral compartments.

Alzheimers disease and related dementias (ADRD)1 and Parkinsons disease and related disorders (PDRD)2 have substantial genetic contributions, yet the role of rare damaging coding variants remains incompletely characterized at population scale3-6. We performed gene-based burden testing of rare loss-of-function and deleterious missense variants using whole-genome sequencing data from large population biobanks combined with disease-specific sequencing cohorts, leveraging proxy phenotypes to maximize statistical power for late-onset neurodegenerative diseases7. We confirmed rare variant burden in established ADRD genes (ABCA7, PSEN1, ADAM10, ATP8B4, GRN, SORL1, TREM2, SHARPIN) and PDRD genes (GBA1, LRRK2). We additionally identified novel associations in ADRD (IMPA2, PMM2, SYNE1, CHRNA4, FCGR1A) and PDRD (ANKRD27, CCL7, USP19, SKP1, KANSL3). The strongest signal was observed for ANKRD27, where damaging variants clustered within domains mediating interactions with Rab GTPases and retromer components. Our results demonstrate the power of population-scale sequencing combined with proxy phenotypes to identify rare coding risk genes for neurodegenerative diseases.