Citations

Krabbe disease (KD) is a rare, inherited leukodystrophy associated with early mortality. Infantile Krabbe disease (IKD) was added to the Recommended Uniform Screening Panel (RUSP) in July 2024. Since then, U.S. states have continued to evaluate implementing KD newborn screening (NBS), and RUSP inclusion has hastened adoption efforts. This study aimed to characterize NBS program responses to this recommendation and identify factors influencing adoption and implementation. A mixed-methods approach was used, including a case review of Wisconsin’s process to add conditions to its NBS panel and a cross-sectional survey of U.S. NBS programs. Responses were obtained from 50 of 51 NBS programs. Twenty-two programs actively screen for KD, with ten additional programs in the implementation process. Screening approaches varied, particularly in psychosine (PSY) cutoff thresholds and testing algorithms. Programs reported a range of adoption pathways, including legislative mandates, advisory committee review, and state-specific nomination processes. Key factors impacting KD NBS adoption included uncertainty regarding treatment safety, efficacy, and availability, ethical considerations related to identifying later-onset disease, and logistical challenges such as laboratory readiness and clinical follow-up resources. This study provides a contemporary overview of national implementation of KD NBS and offers practical insights for programs considering adoption.

Abstract Recent evidence implicates somatic mutations in disease-associated genes across multiple neurodegenerative disorders, including the identification of two somatic TARDBP variants as a putative cause of frontotemporal lobar degeneration with TDP-43 pathology type C (FTLD-TDP type C). However, these findings remain anecdotal. We performed single-nucleus amplicon sequencing of 39,800 neurons from the superior temporal gyrus of sporadic FTLD-TDP type C patients (34,738 neurons, 52 individuals) and non-demented controls (5,062 neurons, 26 individuals) using the Mission Bio Tapestri platform and investigated somatic variants in TARDBP and other FTLD-TDP-associated genes in a case-control setting. We uncovered an extensive landscape of ultra-low-frequency (<1%) somatic mutations across all analysed genes, including TARDBP . Rare somatic occurrences of known ALS/FTD-associated germline TARDBP variants, including p.N267S and p.M337V, were identified exclusively in patients. Among all targeted genes, TARDBP had the highest proportion of neurons harbouring a somatic variant, and this mutational burden was lower in individuals who died at an older age. Strikingly, the C-terminal domain of TDP-43, where most ALS/FTD germline pathogenic variants reside, exhibited a lower neuronal mutational burden than its other domains. This suggests that neurons harbouring damaging mutations may undergo progressive loss prior to autopsy, leaving only rare survivors at frequencies too low to detect by bulk or small-scale single-cell approaches. Together, our findings provide an unprecedented resolution into the somatic mutational landscape of post-mitotic neurons in FTLD-TDP type C and reveal a gene-specific layer of neuronal mosaicism that current single-cell WGS studies fail to detect.

Abstract Purpose Bevacizumab is an effective treatment for radiation necrosis; dose dependent radiographic and edema response data are lacking. Methods Multicenter, retrospective cohort study of adult patients with primary central nervous system tumors or brain metastases who received bevacizumab for radiation necrosis between June 2021 and July 2024. Patients were grouped by bevacizumab dose (7.5 mg/kg vs 10 mg/kg administered every three weeks). Primary outcome was edema response, assessed by a blinded neuro-oncologist. Secondary outcomes included contrast enhancing disease response, clinical response, adverse events, treatment discontinuation, and re-dosing for recurrent radiation necrosis. Analyses were performed with and without adjustment for tumor type. Results 104 patients were included (7.5 mg/kg, n = 53; 10 mg/kg, n = 51). Edema response differed between dosing groups in unadjusted analyses (p = 0.032), favoring the 7.5 mg/kg cohort; however, this association was attenuated after adjustment for tumor type. Contrast enhancing disease response did not differ between groups in either unadjusted or adjusted analyses (p = 0.43). Clinical response was higher in the 7.5 mg/kg group (65.2% vs 37.8%, p = 0.013). Tumor type differed significantly between cohorts (p < 0.001), with more primary CNS tumors in the 10 mg/kg group. Rates of adverse events, treatment discontinuation, and re-dosing were similar. Conclusions While lower-dose bevacizumab was associated with greater edema reduction in unadjusted analyses, this effect was attenuated after accounting for tumor type. Importantly, 7.5 mg/kg dosing appeared sufficient for achieving edema control and contrast enhancing disease response. These findings support an individualized approach to bevacizumab dosing in radiation necrosis and highlight the need for prospective, tumor-stratified studies.

Purpose: Compared with white-light cystoscopy (WLC), blue-light cystoscopy (BLC) enhances detection of non–muscle-invasive bladder cancer (NMIBC), especially carcinoma in situ (CIS). However, its effects on health care resource utilization and cost burden have not been fully elucidated. This study assessed the economic implications of BLC vs WLC. Materials and Methods: We conducted a retrospective cohort analysis with claims data from the Optum Research Database between June 2011 and May 2023. Patients who underwent BLC or WLC were identified, and white-light patients were matched 6:1 to blue-light patients by index year and time between bladder cancer diagnosis and cystoscopy. Inverse probability of treatment weighting was used to adjust for baseline differences. Health care resource utilization and total and bladder cancer–specific costs were calculated on a per-patient-per-month basis. Results: The final cohort included 794 blue-light and 4764 white-light patients. Before weighting, claims coded for CIS were more frequent in blue-light patients (19.6% vs 8.8%; P < .001). Blue-light patients underwent more upper-tract imaging (71.8% vs 57.8%; P < .001), BCG (24.2% vs 15.8%; P < .001), and biomarker testing (65.0% vs 34.9%; P < .001). After weighting, blue-light patients had a higher mean number of bladder cancer–related ambulatory visits per month (1.3 vs 1.0; P = .004). However, neither all-cause health care resource utilization (3.47 vs 3.21; P = .11) nor total cost ($2987.93 vs $2886.16, per patient per month, P = .65) differed significantly between cohorts. Conclusions: BLC is associated with greater health care resource utilization for NMIBC without significantly elevating health care costs, suggesting that enhanced diagnostic strategies can be implemented without added financial burden in real-world practice.

White matter hyperintensities (WMHs) are common MRI findings and established markers of cerebral small-vessel disease associated with stroke, cognitive decline, and vascular risk factors. Several studies have suggested that individuals with migraine, particularly migraine with aura (MA), may have an increased burden of WMHs compared with individuals without migraine. Early population-based studies and meta-analyses reported a higher prevalence of WMHs in migraine, whereas more recent large neuroimaging cohorts have reported conflicting findings or no association. Differences in study design, migraine ascertainment, MRI acquisition parameters, WMH quantification methods, and adjustment for vascular risk factors complicate interpretation of the existing literature. An updated systematic review focusing on methodologically comparable population-based cohorts is therefore warranted. The primary objective of this systematic review and meta-analysis is to determine whether adults with migraine have a higher prevalence or burden of WMHs on MRI than non-migraine controls. Secondary objectives include evaluating associations according to migraine subtype (MA vs. migraine without aura and episodic vs. chronic migraine), sex, WMH location, age, and MRI acquisition or WMH quantification methods, as well as examining longitudinal WMH progression where available. We will include population-based cross-sectional or longitudinal cohort studies of adults undergoing brain MRI with sequences suitable for WMH detection. Migraine exposure may be defined using International Classification of Headache Disorders criteria, structured interviews, validated questionnaires, physician diagnosis, or ICD codes. Controls must originate from the same source population. Searches will be conducted in PubMed/MEDLINE, EMBASE, Web of Science, and Scopus. Study selection, data extraction, and risk-of-bias assessment will be performed independently by two reviewers using Covidence, and risk of bias will be evaluated using the ROBINS-E tool. Because WMH burden is reported using heterogeneous metrics across studies, the primary synthesis will use a precision-weighted direction-of-effect approach, in which each study contributes the direction of the association, weighted by statistical precision. Where sufficiently comparable outcomes are available, random-effects meta-analysis will be performed. Sensitivity analyses will explore the influence of diagnostic criteria, MRI field strength, and confounder adjustment. This review will provide an updated and methodologically rigorous synthesis of the evidence on the association between migraine and WMHs.

Abstract Cellular senescence has been implicated in the pathophysiology of radiotherapy-associated bone loss. Based on our previous work, clearance of senescent cells using genetic and pharmacological tools alleviates the anomalies associated with radiation-associated bone deterioration. The pro-inflammatory senescence associated secretome referred to as senescence associated secretory phenotype (SASP), is a hallmark of cellular senescence. The modulation of SASP by senomorphic drugs, potentially can suppress the pro-inflammatory secretome of senescent cells, irrespective of the underlying senescence mechanism. In this study we tested a senomorphic drug, ruxolitinib, a Janus kinase inhibitor (JAKi), during acute and chronic radiotherapy related effects on the bone. Our clinical data indicate an early increase in several pro-inflammatory SASP proteins following radiotherapy of spinal metastasis in prostate cancer patients. Longitudinal assessment of SASP-related genes confirmed this acute elevation in several SASP markers in systemic circulation following irradiation of male mouse femurs. In studies done in male mice, following three preclinical radiotherapy regimens of 30Gy (5 x 6Gy), 60Gy (5 x 12Gy) and a single dose of 24Gy, suppression of SASP by JAKi was efficacious in suppressing radiation-induced bone damage. In comparison and as shown before, the senolytic combination of D+Q was also able to alleviate radiation-associated bone loss. Early and intermittent suppression of SASP using JAK inhibitors in male mice alleviated chronic bone deterioration, diminished telomere dysfunction, lowered senescence and SASP marker expression and reduced bone-marrow adiposity. Overall, our study shows that early targeting of SASP proteins could be a potential therapeutic to prevent radiotherapy-related chronic bone loss and risk of fractures.

Abstract White matter bundles play a crucial role in cognitive functions by rapidly transmitting information between brain regions. Inter-areal conduction guides the integration of information and conduction velocity is a fundamental parameter in theories and models of brain function. However, distributions of conduction velocity remain difficult to characterize in vivo in humans. In this work, we integrated diffusion magnetic resonance imaging (dMRI) tractography with intracranial electrical stimulation during clinical stereo-electroencephalography (sEEG) monitoring in 17 subjects to measure conduction velocity within four major white matter bundles. Our findings reveal that human brain conduction is characterized by high variability both within and between bundles, reflecting a predominance of slow connections alongside rare high-speed connections. Because conduction velocity in myelinated fibers follows an approximately linear relationship with axon diameter, we derive underlying axon diameter distributions and show that these estimates are comparable to previous post-mortem studies. These findings demonstrate a heavily skewed distribution of human neural conduction velocities and show that structural heterogeneity shapes the timing and integration of information in large-scale networks.

Krabbe disease is an autosomal recessive leukodystrophy caused by a deficiency of the lysosomal enzyme galactosylceramidase (GALC), responsible for the degradation of galactolipids, resulting in toxic psychosine accumulation and progressive demyelination of the central and peripheral nervous systems. Newborn screening (NBS) has increased recognition of later-onset Krabbe disease, although interpretation of complex GALC genotypes remains challenging, particularly in the presence of “pseudodeficiency” and modifier alleles. In this case report, we describe a child with late-infantile Krabbe disease identified through NBS with markedly reduced GALC activity and a homozygous GALC haplotype containing c.956A>G (p.Tyr319Cys; Y319C) and c.1685T>C (p.Ile562Thr; I562T), in addition to other benign variants. Retrospective analysis of the newborn screening specimen demonstrated mild psychosine elevation. Despite preserved neurodevelopment, longitudinal surveillance demonstrated progressive cerebral white matter abnormalities by 3 years and 9 months of age and psychosine elevation in erythrocytes (14 pmol/g Hb; controls < 5), prompting umbilical cord blood transplantation (UCBT). Following transplantation, GALC enzyme activity normalized, psychosine levels decreased, and serial neuroimaging demonstrated radiographic stability without neurologic regression at last follow-up (9 years old). This case expands the phenotypic spectrum associated with homozygosity for the p.Tyr319Cys variant and highlights the role of p.Ile562Thr in amplifying the pathogenic potential when in cis with p.Tyr319Cys. This GALC haplotype illustrates how “pseudodeficiency” and modifier alleles may collectively influence biochemical, radiologic, and clinical disease expression. These findings emphasize the importance of integrating genotype, psychosine, enzyme activity, and longitudinal neuroimaging when evaluating infants with NBS results positive for Krabbe disease.

Progranulin (PGRN) deficiency is a common hallmark in frontotemporal dementia (FTD) patients with granulin ( GRN ) mutations (FTD- GRN ). Previous studies by our group and others have observed that reduced PGRN perturbs lysosomal function and microglial activation, which is believed to accelerate neurodegeneration in FTD- GRN patients. Lysosomal function is intrinsically linked to lipid metabolism, and evidence suggests that GRN deficiency can alter lipid profiles in the brain. Unfortunately, studies to date have focused on whole brain or cortical extracts, limiting our ability to assess cell type-dependent changes in lipid metabolism under disease conditions. Here, we employed lipidomic analysis specifically within the pontine microglia of Grn knock-out (KO) mice, a cell population that was previously linked to disease phenotypes in this model. We observed a significant reduction in the endolysosomal lipid bis(monoacylglycero)phosphate (BMP) and the lipid metabolite phosphatidylethanolamine (PE); these microglial-specific lipid alterations mirror previous whole-brain findings, suggesting that similar changes may occur across multiple cell types in the brain. We also detected a significant increase in the myelin-composing factor galactosylceramide (GalCer), which may reflect an aberrant accumulation of myelin debris within microglia that arises due to defective lysosomal clearance. Notably, lipid perturbations were exacerbated with age within Grn KO microglia, suggesting that changes in lipid metabolism are both age- and genotype-dependent in this model. Together, our results support our hypothesis that PGRN acts as a master regulator of critical microglial processes – including lysosomal function, lipid metabolism, and the regulation of myelination – in an age-dependent manner.