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Orphanet Journal of Rare Diseases

Springer Science and Business Media LLC

Preprints posted in the last 90 days, ranked by how well they match Orphanet Journal of Rare Diseases's content profile, based on 21 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

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Reduced PDE4D expression and activity in Acrodysostosis Type 2 patient fibroblasts underlie disease pathology

Gardner, O. F.; Ling, J.; Munkongcharoen, T.; Kyurkchieva, E.; Leitch, H. G.; Wilson, L. C.; Baillie, G. S.; Ferretti, P.

2026-08-11 cell biology 10.64898/2026.08.10.743905 medRxiv
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BackgroundAcrodysostosis type 2 (ACRDYS2) is a rare autosomal dominant disease characterized by skeletal defects and cognitive deficit, with clinical symptoms observed in multiple other tissues including the skin. It is caused by mutations in a phosphodiesterase, PDE4D, a key regulator of cAMP/PKA (cyclic adenosine monophosphate / protein kinase A) signalling. Despite its well-defined genetic causes, the molecular mechanisms underlying the disease remain poorly understood, with studies based largely on engineered cellular models reaching conflicting interpretations. MethodsTo investigate how endogenous dynamics are affected by PDE4D mutations in unmanipulated cells, we studied PDE4D transcript and protein expression, activity and downstream signalling in native dermal fibroblast from ACRDYS2 patients and healthy controls. ResultsSignificant reduction in total PDE4D expression in patient cells was observed both at the transcript and protein level, with marked decreases in the long isoforms PDE4D4 and PDE4D7; a reduction in PDE4D9 mRNA was also observed. PDE4D enzymatic activity was reduced in ACRDYS2 fibroblasts, though total PDE activity was largely preserved. Reduced PDE4D expression was associated with an increase in the phosphorylated form of the cAMP-responsive transcription factor CREB and elevated PRKAR1A (PKA type 1 regulatory subunit alpha) transcript levels, suggesting altered downstream signalling. Interestingly, expression of the related phosphodiesterase family member PDE4B was increased, consistent with a compensatory response to reduced PDE4D function. ConclusionsThis is the first study demonstrating reduced PDE4D expression and isoform-specific dysregulation in native ACRDYS2 cells. Together, our results support a model in which reduction in PDE4D activity and compensatory changes in other PDE4 family members contribute to the molecular pathology of ACRDYS2, providing new insights into the molecular mechanisms underlying this disorder.

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ICD-10 Code Ambiguity Obscures Treatment-Eligible Adults with Spinal Muscular Atrophy: A Single-Center Chart Review and Patient Outreach Study

Holly, G.; Bean, B.; Beshay, H.; Edwards, G.; Streicher, N. S.

2026-06-15 neurology 10.64898/2026.06.07.26355122 medRxiv
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Background. Three disease-modifying therapies (DMTs) for spinal muscular atrophy (SMA) have been approved since 2016, yet many adults remain untreated. Identifying them depends on ICD-10 codes that capture SMA but do not reliably distinguish it from other related conditions. We examined, in one U.S. health system, both patients' engagement with therapy and the accuracy of the codes used to find them. Methods. We conducted a retrospective chart review of adults in an academic health system identified by SMA-associated ICD-10 codes, with manual adjudication of diagnosis and DMT status. Confirmed SMA-positive, DMT-naive patients were invited to a structured telephone interview on treatment awareness and barriers. Results. Of 60 charts, 22 (36.7%; 95% CI 25.6-49.3%) were appropriately coded for SMA or a related disorder; only 16 (26.7%) had molecularly confirmed SMA. The other 38 (63.3%) were miscoded, spanning spinal and bulbar muscular atrophy, asymptomatic carriers, prenatal screening, and conditions unrelated to SMA. Ten of the 16 confirmed patients (62.5%) were DMT-naive; one was interviewed, one declined, and eight could not be reached. The non-response is itself a finding: the patients least visible to administrative data are the hardest to reach. Conclusions. ICD-10 ambiguity is a barrier to treatment access in adult SMA, as is loss to follow-up. We make two recommendations: continuous documentation-coding alignment that uses natural language processing to verify the genetic precondition, and type-specific SMA codes (subcodes for Types 0-4) anchored on molecular SMN1 confirmation. Together these would support cohort identification, outreach, and evidence generation without adding to clinician burden.

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Symptom-based phenotype discovery in motor neuron disease using natural language processing of electronic health records

Abdulle, Y.; Dinu, V.; Wu, J.; Kim, Y.; Budhdeo, S.; Yao, Z.; Tomlinson, C.; Al-Chalabi, A.; Wu, H.; Dobson, R.; Iacoangeli, A.

2026-06-22 neurology 10.64898/2026.06.18.26355960 medRxiv
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Background: Motor neuron disease (MND) is a fatal neurodegenerative condition with significant clinical heterogeneity that is incompletely captured by existing phenotype classifications based on onset site. Electronic health records (EHRs) contain detailed symptom documentation in clinical narratives that may enable data-driven discovery of clinically meaningful patient subgroups. Methods: We developed a natural language processing (NLP) pipeline using MedCAT to extract symptoms from clinical notes of 2,361 people with a confirmed diagnosis of MND at a tertiary neurology center. MND cohort confirmation used three complementary methods: clinic attendance records, text-based diagnosis detection, and NLP extraction with negation detection. Extracted symptoms were filtered to Unified Medical Language System semantic type T184 (Sign or Symptom) with removal of negated concepts. Patients were clustered using latent class analysis on binary symptom profiles. Survival differences were assessed using Kaplan-Meier analysis, log-rank tests, and Cox proportional hazards regression. Results: From the first clinical notes, we identified four clusters of symptoms among 872 patients and 76 symptoms: Motor-Bulbar (n=373), Motor-Tremor (n=154), Sensory-Pain (n=222), and Motor-Respiratory (n=123). When extended to all clinical notes (n=2,065; 184 symptoms), these reorganized into three clusters: Autonomic-Respiratory (n=472), Nocturnal-Respiratory (n=338), and Classic Motor (n=1,255). Survival differences were significant across all clusters in both the first notes and all notes analyses (log-rank p < 0.001). Conclusions: NLP-based symptom extraction from EHRs identifies clinically meaningful MND subgroups that extend beyond traditional onset-site classifications. Autonomic-respiratory symptom burden is associated with poorer survival while a newly identified Sensory-Pain subtype with a better prognosis. These data-driven phenotypes may improve prognostication and inform targeted supportive care.

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Development and Initial Validation of the Quality of life Evaluation in NF2-related Schwannomatosis Trials (QUEST) Assessment

Merker, V. L.; Carias, S. C.; Ferner, R. E.; Golding, J. F.; Plotkin, S. R.; Buono, F. D.

2026-06-18 neurology 10.64898/2026.06.09.26355287 medRxiv
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Individuals with NF2-related schwannomatosis (NF2-SWN) experience a complex constellation of physical, emotional, and social symptoms that substantially impact quality of life (QoL). Although disease-specific patient-reported outcome measures are increasingly important for evaluating treatment benefit in clinical trials, existing NF2-SWN QoL measures have limitations in content coverage and sensitivity to change. This study describes the development and initial validation a new disease-specific QoL assessment -- the Quality of Life Evaluation in NF2-related Schwannomatosis Trials (QUEST). Using a three-phase, mixed-methods approach, items were generated through concept elicitation interviews with individuals with NF2-SWN and clinicians, prioritized via patient survey data, and refined through iterative cognitive debriefing procedures. The resulting 21-item QUEST assesses the extent to which NF2-SWN has negatively impacted a persons daily life over the past seven days. Initial psychometric evaluation was conducted in an international sample of 174 individuals with NF2-SWN aged 15 years and older (117 women (67%), 158 White individuals (89%)). Exploratory factor analysis supported a four-factor structure, and the total score demonstrated excellent internal consistency and strong test-retest reliability. Evidence of construct validity was demonstrated through hypothesized associations with disease-specific, generic, and domain-specific QoL measures, as well as known-groups validity based on self-reported disease severity and number of prior surgeries. Incremental validity analyses indicated that QUEST explained unique variance beyond existing measures. Together, findings support the QUEST as a reliable and valid disease-specific QoL measure with strong content validity and feasibility for use as a clinical trial endpoint in NF2-SWN.

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The vanishing white matter registry: a case study of historical controls in clinical trial design

van Voorst, R. J.; Gonzato, E.; Hamilton, E. M. C.; Stellingwerf, M. D.; Postema, M. C.; Berkhof, J.; van Eekelen, R.; van der Knaap, M. S.

2026-08-22 neurology 10.64898/2026.08.19.26360800 medRxiv
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Background: Therapy development in ultra-rare, progressive and fatal diseases like vanishing white matter (VWM) is hampered by very low patient numbers and ethical constraints regarding placebo-controlled studies. Under such conditions, standard randomized controlled trials may not be feasible. The use of historical control information could be part of a solution, but would require extra considerations regarding selection of patients and choice of endpoints. We used the VWM registry as a case study to outline key methodological considerations for informing trial design in ultra-rare disease. Methods: The study included 462 patients, available in the VWM registry. Prospective clinical data were collected since 2004 using VWM-specific questionnaire and Health Utility Index (HUI) assessments, while retrospective data from clinical charts were available from 1988 on. We evaluated methodological aspects relevant to trial design, including patient selection, drift in the disease course over time, endpoint selection, and clinically relevant stratification into subgroups. Results: Regarding patient selection, patients with comorbidities impacting disease course, and pre-symptomatic individuals without clinical onset were considered not suitable as historical controls. After excluding patients before 1991, we found no evidence of drift in the disease course from 1991 onwards. Regarding choice of endpoints, episodes of rapid decline were relatively infrequent and occurred mostly at disease onset, limiting their usefulness as trial endpoint. Multi-state modelling and clinical evaluation showed ambulation as preferable endpoint over survival. For longitudinal HUI multiscores, baseline imputation allowed modelling of early disease. The scores showed a distinct ordering, reflecting the association between multi-domain function and disease progression. Regarding stratification, the combination of data-driven analyses and clinical expertise informed revised age of onset groups. Females showed later onset and milder disease; adjustment for age of onset eliminated the effect of sex. Conclusion: This case study provides key considerations for evaluating registry data as historical control and demonstrates how these considerations can inform clinical trial design in ultra-rare diseases.

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From genes to pathways: genetic convergence in early-onset Parkinsons disease in India

Menon, R.; Khan, A. I.; Elangovan, D.; Kandadai, R. M.; Goyal, V.; Desai, S. D.; Joshi, D.; Kumar, H.; Wadia, P. M.; Mukherjee, A.; Kumar, N.; Mehta, S.; Geetha, T. S.; Sandeep, C.; Murugan, S.; Ayathu Venkat, M.; Shah, H. S.; Paramanandam, V.; Chandarana, M. v.; Yadav, R.; Dhamija, R. K.; Pal, P. K.; Biswas, A.; Gupta, R.; Borgohain, R.; Vedam, R. L.; Kukkle, P. L.

2026-09-03 neurology 10.64898/2026.08.31.26361762 medRxiv
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Parkinsons disease (PD) arises through disruption of multiple interconnected cellular processes, but the genetic contributions to these processes may differ across ancestries. We investigated functional convergence among genes harboring pathogenic or likely pathogenic (P/LP) variants and variants of uncertain significance (VUS) in a multicenter Indian cohort recruited through the Genetics of Parkinsons Disease in India Young Onset Parkinsons Disease project (GOPI YOPD). The cohort included 668 participants (463 males 69.3%) with a mean age at motor onset of 39.4+/-8.8 years. P/LP variants and VUS identified through previously reported whole-exome or whole genome sequencing were retained as separate evidential categories. The P/LP-associated gene set comprised 11 unique genes and the VUS associated set comprised 40 unique genes. Separate STRING functional-enrichment analyses evaluated Gene Ontology Biological Process, Molecular Function and Cellular Component terms, KEGG pathways, WikiPathways and STRING local network clusters. Terms meeting a Benjamini Hochberg false discovery rate threshold of <0.05 were organized into eight non-mutually-exclusive ontology/pathway categories. Gene to pathway mappings were subsequently projected to individual participants to estimate pathway representation and examine clinical associations. At least one reportable P/LP variant or VUS was identified in 336/668 participants (50.3%): 35 had a P/LP variant alone, 282 had VUS alone and 19 had a P/LP variant together with VUS in one or more additional genes. The most frequently represented categories were mitochondrial organization (247/336, 73.5%), autophagy related processes (228/336, 67.9%) and regulation of synaptic vesicle transport (201/336, 59.8%). PRKN was the most frequent P/LP-associated gene, occurring in 29/54 P/LP carriers, followed by PLA2G6 and PINK1. Lysosomal transport was represented exclusively by VUS-associated genes, particularly GBA1, VPS13C and LRRK2. Among P/LP carriers, additional VUS in distinct genes were not associated with age at onset (P = 0.81) or family history (52.6% versus 31.4%; P = 0.15). No pathway phenotype association remained significant after correction for multiple testing. Genetic findings in this Indian cohort converged across an interconnected mitochondrial autophagic lysosomal vesicular network, with different contributions from P/LP-associated and VUS associated gene sets. This study provides the first pathway resolved South Asian genetic profile and a framework for comparative studies across populations.

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Cellular Morphology and Motility Defects are Conserved Phenotypes of Trisomy 21 Despite Heterogeneous Adhesion Mechanisms

Rygel, K.; Chambers, K.; Yoon, B.; Agrawal, M.; Bailey, S.; Patel, M.; Wolfe, C.; Montazzoli, A.; Bumbledare, T.; Cassidy Malcom, P.; Kelemen, S.; Neifert, C.; Headen, J.; Kershner, L.; Kirkise, N.; Welshhans, K.

2026-08-04 cell biology 10.64898/2026.08.03.742622 medRxiv
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Down syndrome is a neurodevelopmental disorder caused by the trisomy of human chromosome 21 (T21). Down syndrome is associated with a wide range of variable clinical features, including congenital heart defects and slow wound healing; however, intellectual disability is ubiquitous and results, in part, from altered neuronal connectivity. Here, we used three sets of control and T21 human fibroblasts, and one set of human induced pluripotent stem cell (hiPSC)-derived cortical neurons, to examine whether changes in cellular morphology and motility are consistent across cell types in Down syndrome and to elucidate the underlying mechanisms. We found that fibroblast morphology is dysregulated in all T21 fibroblast lines. Using a transwell migration assay, cellular migration is decreased in two of the three T21 fibroblast lines. T21 hiPSC-derived cortical neurons also exhibit morphological defects, including a decrease in the length of the longest neurite and growth cone area. Because of these significant changes in morphology and motility in T21 cells, we examined proteins in the focal adhesion complex, which links the intracellular cytoskeleton to the extracellular matrix and directly controls these processes. Multiple proteins in the adhesion complex, including paxillin, vinculin, talin, and RACK1, are dysregulated in T21 fibroblasts and hiPSC-derived neurons, but these changes have high inter-individual variability. Taken together, these findings suggest that altered cellular morphology and motility are conserved features of Down syndrome that arise through heterogeneous alterations in adhesion networks. Thus, this work significantly contributes to the recent literature highlighting the need for personalized medicine in Down syndrome.

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Consensus Recommendations for the Clinical Management of Wolfram syndrome Using a Delphi Method

Urano, F.; Elliott, J.; Ahmadi, S.; Yu Wai Man, P.; Gladstone, S.; Gebel, S.; Lynch, T.; Barrett, T.; International Wolfram Syndrome Clinical Guidelines Consortium,

2026-07-02 genetic and genomic medicine 10.64898/2026.07.02.26357130 medRxiv
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Background: Wolfram syndrome is a rare neurodegenerative disorder, most commonly caused by pathogenic variants in WFS1, while cases due to CISD2 are exceedingly rare. The estimated prevalence is 1 in 160,000 to 770,000 individuals worldwide. In these clinical guidelines, disorders caused by WFS1 are referred to as WFS1-Wolfram syndrome, and those caused by CISD2 as CISD2-Wolfram syndrome. Historically, it has been characterized by early-onset, antibody-negative, insulin-dependent diabetes mellitus, progressive optic atrophy, sensorineural hearing loss, arginine vasopressin deficiency, and brainstem and cerebellar atrophy. More recently, partial and late onset forms have been identified. There are currently no licensed disease-modifying treatments, and international clinical guidelines have not previously been established. Methods: An international steering committee systematically reviewed 273 peer-reviewed publications and generated draft consensus statements across six clinical domains. These statements were evaluated by international specialists in endocrinology, clinical genetics, neurology, ophthalmology and neuro-ophthalmology, psychiatry, and urology, drawn from North America, Europe, Latin America, Oceania, and Asia, using a modified three-round Delphi process. Additional feedback was incorporated from nurses specializing in multidisciplinary Wolfram syndrome care, from leaders of international patient organizations, and from specialists in the genetic diagnosis of monogenic diabetes. Structured feedback from patients and families was gathered through multiple international patient advocacy organizations. Consensus was defined as [&ge;]80% agreement. Results: All 35 final consensus statements reached the pre-specified consensus threshold of [&ge;]80% agreement, spanning diagnosis and genetic testing, multidisciplinary care organization, neuro-ophthalmology, neurology, endocrinology, urology, gastroenterology, and psychiatry. Conclusions: These guidelines are the first international clinical consensus for Wolfram syndrome and provide actionable recommendations for clinicians worldwide. Implementation should be accompanied by a prospective audit to expand the evidence base and support future iterations.

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Project ECHO for patients with chronic intestinal failure: Empowering people living with rare disease using a virtual telelearning model

Iyer, K.; Winkler, M.; Fisher, E.; Kumpf, V.; Nair, M.; Kakani, S.; Poindexter, K.; Jablonski, A.; Hoopes, E.; Ballog, P.; Nisenholtz, M.; Friebel, R.; Yiannoutsos, C.; Lai, J.; Tappenden, K.

2026-08-28 health systems and quality improvement 10.64898/2026.08.25.26361379 medRxiv
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Background: Chronic intestinal failure is a devastating rare disease in which patients require complex and life-saving parenteral nutrition or intravenous fluids delivered through a central venous catheter. There is a shortage of clinical expertise to manage chronic intestinal failure and patients in the United States lack access to the limited number of expert care centers. We developed a patient intestinal failure (PIF) ECHO intervention with patient advocates who have lived experience with the goal of connecting patients and family caregivers virtually to multidisciplinary intestinal failure experts for best practice learning. Objective: We pilot-tested the acceptability and feasibility of a direct-to-patient telelearning program based on the well-established ECHO Model focused on best practices in chronic intestinal failure care. Setting and Participants: 19 adults with chronic intestinal failure attended the pilot PIF-ECHO program for 12 consecutive weeks via Zoom between April and July 2026. All participants completed the post intervention questionnaire and 16 individuals participated in 3 focus groups. Design: A mixed methods evaluation was conducted. Questionnaires were assessed according to seven domains of the Theoretical Framework of Acceptability and qualitative data from the virtual focus groups were coded and analyzed using iterative thematic analysis. A data-derived PIF-ECHO logic model was developed to illustrate pathways between the program content and anticipated outcomes. Results: There was strong or very strong agreement that sessions were accessible, enjoyable, worth the time spent, and improved understanding of intestinal failure and its management. Information learned increased confidence for self-advocacy in navigating healthcare needs, disease and therapy self-management, and improved well-being. Interaction with facilitators, expert presenters, and peers was positive, judgement free, validating, and respectful. Participants felt empowered and reported lower levels of emotional strain due to the supportive resources and knowledge gained. Conclusions: A patient-facing tele-learning program in chronic intestinal failure is feasible, accessible, and acceptable to patients and appears to result in important short-term and medium-term benefits. The program was perceived as valuable and notably different from patient and peer-led support groups. The model could be applied more widely to other rare diseases. Lived Experience and Patient Contributions: Four patient advocates with lived experience in chronic intestinal failure were involved throughout the study including pre-study interviews and focus groups to inform PIF-ECHO design and content, recruitment, as presenters on topics of self-advocacy and role of patient support groups, and in the analysis and refinement of the program logic model. Their input shaped the relevance and acceptability of the PIF-ECHO pilot program. All four patient advocates fulfil uniform requirements for authorship and are co-authors on this paper. This work documents a meaningful partnership in the creation of a patient-facing virtual tele-learning adaptation of the ECHO model and establishes a valuable collaboration for future study of PIF-ECHO on a larger scale.

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More Than Results: A Qualitative Study on the Role of Person-Centered Genetic Counseling in Parkinson Disease Research

Verbrugge, J.; Fiallos, K.; Cook, L.; Miller, M.; Head, K. J.

2026-06-09 genetic and genomic medicine 10.64898/2026.06.03.26354465 medRxiv
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As genetic testing becomes increasingly integrated into Parkinson disease (PD) research, including targeted testing for variants in LRRK2 and GBA1, the return of individual research results is becoming more common. However, limited qualitative data exists regarding how research participants experience genetic results disclosure and post-test genetic counseling in PD research settings. We conducted semi-structured qualitative interviews with participants (n=13) enrolled in the Parkinson Precision Medicine Initiative (formerly Parkinson Progression Markers Initiative; PPMI) who had received PD-related genetic test results and post-test genetic counseling. Interviews were conducted 1 to 3 weeks following result disclosure and analyzed using thematic analysis with a primarily deductive coding approach informed by study aims and inductive identification of emergent themes. Four primary themes were identified: (1) personal connection and motivations for participation, (2) centrality of result disclosure and information preferences, (3) emotional experiences and support needs, and (4) communication quality and alignment with participant needs. Overall, our findings underscore the importance of person-centered genetic counseling within PD research. As return of genetic and biomarker results in research and clinical trial contexts expand, thoughtful integration of relational, informational, and communication-focused practices will be essential to support participant engagement and trust.

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Patient Perspectives on Potential Implementation of Coordinated Family Care Visits for Inherited Cardiovascular Disease

Draisin, E. R.; Badar, H.; Naik, H.; Platt, J.; Kaufman, B.; Salisbury, H.; Ison, H. E.

2026-08-07 cardiovascular medicine 10.64898/2026.08.05.26359830 medRxiv
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Introduction: Shared medical appointments (SMAs) are medical visits where multiple individuals are seen together in a group setting. For patients with inherited cardiovascular disease, where multiple family members often require ongoing cardiac care and screening, family SMAs may be particularly valuable as a tool to facilitate family communication and comprehension of their condition. This research aimed to identify patient perspectives on the potential benefits and challenges of family SMAs in comparison to an existing individual clinic model. Methods: Qualitative semi-structured interviews were conducted with adult family representatives. Each family had at least one family member seen at the adult and pediatric inherited cardiovascular disease clinics. Interview recordings were transcribed verbatim and inductively coded using a content analysis approach. Results: Sixteen families were interviewed in this study. The mean age of the family representative interviewed was 43.4 years ({+/-} 9.3 SD), and they were followed at Stanford Health Care for a mean of 7.3 years ({+/-} 4.2 SD). 81.2% (13/16) of families said they would find family SMAs beneficial. For interested families who consented to recorded interviews (n=12), benefits and challenges fell into two major categories: care quality and access and logistics. Interested families thought family SMAs would provide an added care quality benefit by increasing understanding among adults, children, and providers (83.3%, 10/12). Six of twelve participants interested in having family SMA visits felt there would be logistical/access-based benefits to this new model (50%, 6/12). Families also identified possible challenges with this model, such as less individualized care, potential privacy concerns, and concerns regarding the smoothness of the clinic process in coordinating a family SMA. Conclusion: The majority of families believed a family SMA model would provide added benefit to families with inherited cardiovascular disease, but requires thoughtful implementation and should be tailored to families? unique needs.

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Genetic Counselor Utilization Across Non-Genetics Departments for Neurodevelopmental Disorders

Cole, J. J.; Cohen, J. S.; Sahin, M.; Srivastava, S.; Campbell, C. A.

2026-07-21 genetic and genomic medicine 10.64898/2026.07.20.26358492 medRxiv
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IMPORTANCE: Most United States children with neurodevelopmental disorders have not received genetic testing aligned with current guidelines. Integration of genetic counselors into non-genetics departments is a potential strategy to improve uptake, but prevalence and details of integrated care models are unknown. OBJECTIVE: To characterize availability, utilization, and perceived need for genetic counselors across non-genetics departments caring for patients with neurodevelopmental disorders DESIGN: Cross-sectional observational department-level survey SETTING: Child neurology, adult neurology, developmental pediatrics, child psychiatry, and adult psychiatry departments at Intellectual and Developmental Disabilities Research Centers PARTICIPANTS: The survey was distributed to 67 departments across 15 institutions. The departmental response rate was 52% (35/67), with at least one response from 87% (13/15) of institutions. EXPOSURE: Presence/absence of dedicated genetic counselor(s), where "dedicated" was defined as hired by the department MAIN OUTCOME(S) AND MEASURE(S): This was a descriptive study only, with no comparative statistical analyses due to the exploratory nature. RESULTS: One third of departments (34%; 12/35) reported having dedicated clinical genetic counselors. Prevalence was highest in child neurology (67%; 8/12), followed by adult neurology (40%; 2/5) and developmental pediatrics (22%; 2/9), with none in child psychiatry (0/7) or adult psychiatry (0/2). In almost all departments with genetic counselors (92%; 11/12), they directly billed for their services, which universally included pre-test counseling/consent and post-test counseling. In departments without genetic counselors, only 39% (9/23) reported providers ordered their own genetic testing. Among all departments, over half (57%) were interested in adding/increasing genetic counseling support, while 26% were unsure and 17% uninterested. Insufficient funding was the most cited barrier; only one department reported insufficient need. CONCLUSIONS AND RELEVANCE: Though currently implemented in only one third of departments, our findings suggest those with dedicated genetic counselors directly pursue genetic testing (without referring to genetics) more than those without genetic counselors. Interest in increasing or adding genetic counseling support was high, and though funding was a reported barrier, feasible funding models were described. In the context of limited medical geneticists and expanding precision therapies, alternate delivery models for neurodevelopmental genetic testing including genetic counselor integration in non-genetics departments may help to scale and sustain uptake.

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Clinical deep sequencing to diagnose pathogenic mosaic variants in malformations of cortical development and epilepsy

Stone, K.; Prinzing, G.; Lai, A.; Smith, L.; Sheidley, B. R.; Corliss, M. M.; Bowling, K.; Cao, Y.; Wiltrout, K.; Stone, S. S. D.; Lidov, H.; Yang, E.; Poduri, A.; D'Gama, A. M.

2026-09-03 neurology 10.64898/2026.09.01.26361943 medRxiv
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Background and Objectives: Deep sequencing of brain tissue in the research setting has established that mosaic variants are a major cause of malformations of cortical development (MCDs) and epilepsy. However, genetic testing in the clinical setting primarily detects germline variants using clinically accessible samples. We aimed to determine the diagnostic yield and clinical utility of deep sequencing in the clinical setting to identify pathogenic mosaic variants for this population. Methods: We performed a retrospective cohort analysis of individuals at Boston Children's Hospital with MCDs with or without epilepsy who received clinical deep sequencing between September 2017 and February 2026. Demographic, clinical, and genetic testing data were abstracted from the medical record. For individuals without systemic features, we classified brain tissue as an affected tissue sample. For individuals with systemic features, we classified brain or relevant non-brain tissue as affected. The primary outcome was the diagnostic yield of clinical deep sequencing performed using affected vs unaffected tissue samples. The secondary outcome was the clinical utility of genetic diagnoses. Results: Our cohort included 37 individuals (19/37 (51%) female, 18/37 (49%) male) with MCDs, of whom 35/37 (95%) had epilepsy (25 with brain tissue samples available from epilepsy surgery) and 8/37 (22%) had systemic features. Most (35/37 (95%)) had dysplasia phenotypes on MRI and 12/27 (44%) with pathology available had Focal Cortical Dysplasia Type I or II. The diagnostic yield was 53% (17/32; 16 mosaic and 1 germline variant) when clinical deep sequencing was performed using an affected tissue sample vs 0% (0/6) using an unaffected tissue sample (p=0.016). Of the diagnosed cases, 13/17 (76%) had testing performed on brain tissue (1 with systemic features) and 4/17 (24%) on non-brain tissue (3 buccal and 1 duodenal tissue, all with systemic features). All but one diagnosis involved the mTOR pathway. All diagnoses had clinical utility. Discussion: Clinical deep sequencing, when performed using an affected tissue sample, has high diagnostic yield and clinical utility for individuals with MCDs, especially dysplasia phenotypes, and epilepsy. Our findings support implementation of clinical deep sequencing for this population, especially as the genetic diagnoses have implications for emerging precision therapies.

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Tracking Neural, Sensory, and Sensorimotor Adaptation to Progressive Vision Loss in Inherited Retinal Dystrophies: A Multimodal Longitudinal Study Protocol

Verroca, A.; Franchin, E.; Mele, S.; Siviero, I.; Busch, I. M.; Benamati, A.; Sanchez-Lopez, J.; Quisisana, C.; Filosa, A.; Marino, V.; Colombo, L.; Cesari, P.; Rimondini, M.; Dell'Orco, D.; Cecchini, M. P.; Mazzi, C.; Savazzi, S.

2026-08-19 ophthalmology 10.64898/2026.08.18.26360630 medRxiv
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Individuals with inherited retinal dystrophies (IRDs) undergo a slow, genetically heterogeneous loss of vision, yet how the visual cortex and non-visual sensory, motor, and psychological systems adapt to this deprivation remains poorly characterized. Existing evidence comes mainly from single-modality, cross-sectional studies that rarely account for genetic heterogeneity, making it hard to distinguish adaptive change from a direct, non-retinal mutation effect, since several IRD genes are not retina-specific. To address this gap, we designed an observational, longitudinal, multimodal protocol that combines ophthalmological, genetic, and in silico characterization with electrophysiological (steady-state visual evoked potentials and TMS-EEG), chemosensory, sensorimotor, and psycho-personological assessments. Patients aged 18 to 75 years with rod-cone (retinitis pigmentosa, Usher syndrome) or cone and cone-rod dystrophies will be assessed at baseline (T0) and at an 18-month follow-up (T1); sighted controls, matched for age, sex, and handedness, will complete the same battery once. Importantly, pairing genotypic with phenotypic data allows changes in non-visual domains to be interpreted against, rather than independently of, each patient's molecular background. We expect individuals with IRDs to differ from controls in visual cortical responsiveness and in selected non-visual sensory and sensorimotor measures, with genotype-related differences explored where sample size permits. Given the rarity of IRDs, the design is exploratory and emphasizes effect sizes and individual variability over large-sample inference. The protocol was approved by the Ethics Committee of the University of Verona (CARP 08.R1/2024) and follows the Declaration of Helsinki and the GDPR; findings will be disseminated through peer-reviewed publications and shared with patients and IRD patient associations.

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Cell line resources for the study of neurofibromin: functions, phenotypes, and drug discovery/development

Liu, H.; Liu, J.; Li, C.; Luppi, E.; Rayat-Sanati, K.; Awad, E.; Westin, E.; Bedwell, D.; Hartman, M.; Leier, A.; Anastasaki, C.; Gutmann, D. H.; Kesterson, R.; Wallis, D.

2026-08-19 genetics 10.64898/2026.08.13.743550 medRxiv
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Our labs have been studying neurofibromin function and phenotype for over a decade with the intent of generating targeted therapeutics for Neurofibromatosis type 1 (NF1). In the process, we have generated numerous human cell lines containing variants within the NF1 gene. Herein, we present data characterizing these cell lines and make them publicly available for use by researchers both within and outside the NF1 community. We describe lines that contain both well-characterized patient-specific variants either at their endogenous locus or as exogenous cDNAs, as well as variants of uncertain significance (VUS), engineered as heterozygous, homozygous, and compound heterozygous variants. Methods to generate each line and subsequent validation steps are detailed including targeted sequencing, Western blot analysis for neurofibromin expression and ERK activation. The utility of each line is dependent on the variant of interest, the parental cell line, and the mechanism of action relevant to possible therapeutic targeting.

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Rethinking supported self-management for Black people living with stroke: the relevance of social, cultural and historical racial context

White, J.; Livingstone, L.; Cramp, M.; Dodd, E.; Vandrevala, T.

2026-07-16 health systems and quality improvement 10.64898/2026.07.16.26357926 medRxiv
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Objectives Despite their higher risk of stroke and known inequities in post-stroke outcomes, research amongst minoritised ethnic communities who have experienced stroke is scarce. This study aimed to explore the experiences of Black people in England and identify implications for supported self-management. Methods Between December 2023 and June 2024 qualitative interviews were conducted with 20 Black people living with stroke in England. Interviews were conducted in-person or online, depending on participants preferences. Data were analysed iteratively using reflexive thematic analysis. Results Three themes were developed: (1) My world after stroke capturing emotional and social identity-related impacts and adjustments; (2) My support: Family, Community and Peers, encapsulating different facets of support and the relational nature of self-management; and (3) Supported self-management as a negotiated partnership with healthcare professionals, highlighting the varied nature and outcomes of patient-professional interactions and their social embeddedness, including underlying power and historical racial dynamics. Conclusions Our study confirms the need for closer examination of how supported self-management can be provided to different populations. The post-stroke experiences of the Black people who participated in our study were inextricably shaped by their specific familial, social and cultural settings. Their adaptation to and management of the physical and emotional aspects of their condition was enacted across family systems, community and peer networks as well as healthcare services, with varying outcomes. In addition, their interactions and engagement with healthcare professionals were influenced by a broader historical context of discrimination and racism. Our study reveals the importance of delivering supported self-management to Black people living with stroke which responds to their specific social contexts and intersectional identities and which also strives to reduce power imbalances and address historical discrimination, thereby ensuring cultural safety in service provision. Overlooking these aspects risks undermining self-management and underserving those who already face significant health inequities.

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"Shifting and sharing the power" in research: Views and perspectives on research priorities from the Down syndrome, Fragile X syndrome and Williams syndrome communities

Cristescu, L.; Pellicano, E.; Van Herwegen, J.; Scerif, G.; Farran, E. K.

2026-08-23 psychiatry and clinical psychology 10.64898/2026.08.20.26360980 medRxiv
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People with intellectual disabilities and their communities are rarely involved in setting priorities for research. Our study addressed this gap through consultations with the UK communities of three genetic syndromes in which intellectual disabilities are common: Down syndrome (DS), Fragile X syndrome (FXS) and Williams syndrome (WS). The study aimed to provide an understanding of (1) the views of the DS, FXS and WS communities on current UK research; (2) their priorities for future research; and (3) participants views of engaging with UK research. We conducted focus group discussions with 39 community members including: children and adults with DS, FXS and WS; parent/carers of people with DS, FXS and WS; practitioners and researchers who work with these communities. Our study was carried out in collaboration with a Steering Group and two Advisory Groups of DS, FXS and WS community members. We identified three themes. First, participants shared their dissatisfaction with the current research landscape and wanted a more balanced landscape, with more research with direct application to the daily lives of people with DS, FXS and WS. Second, community members emphasised the importance of translating research into practice, advocating for better access to research and more meaningful participation to research of individuals with lived experience. Third, our study not only identified what should be the focus of future research on DS, FXS and WS, but also how researchers should conduct their research. Whilst including children in our sample was a strength, there were some limitations to the diversity of our sample; children with FXS were not represented and gender, ethnic and geographic diversity could have been broader. Nevertheless, we hope that our findings will change the future of research in this field so that research carried out in the name of individuals with intellectual disabilities such as DS, FXS and WS, is of direct use to these communities.

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Evaluation of Corneal Subbasal Nerve Plexus Alterations in ARSACS and SPG7 by In Vivo Corneal Confocal Microscopy

Guleser, U. Y.; Akkaya, N.; Kesim, C.; Cakmak, O. O.; Karslioglu, M. Z.; Basak, A. N.; Ertan, S.; Hasanreisoglu, M.; Vural, A.

2026-06-24 ophthalmology 10.64898/2026.06.22.26356257 medRxiv
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Purpose: To investigate corneal subbasal nerve plexus alterations using in vivo corneal confocal microscopy (IVCM) in patients with Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) and Spastic Paraplegia Type 7 (SPG7). Methods: This cross-sectional pilot study included eight ARSACS patients, five SPG7 patients, and twenty age- and sex-matched healthy controls. All participants underwent neurological and ophthalmological examination followed by central corneal imaging using IVCM. Quantitative corneal nerve parameters were analyzed with automated software, and correlations with clinical severity scales were assessed. Results: The mean age was 34.2 +/- 3.4 years in controls, 34.5 +/- 0.7 years in the ARSACS group, and 38.2 +/- 3.5 years in the SPG7 group. Corneal nerve branch density (CNBD) and corneal nerve total branch density (CTBD) were significantly lower in ARSACS and SPG7 patients compared with healthy controls. CNFD, CNFL, CNFA, CNFW, and CNFrD were lower in ARSACS and SPG7 patients compared with healthy controls; however, these differences did not reach statistical significance. No statistically significant differences in IVCM parameters were detected between ARSACS and SPG7 patients. Spearman correlation analysis did not show significant correlations between corneal nerve parameters and FARS, SARA, ADL scores, or disease duration. Conclusion: IVCM revealed reduced corneal nerve branching parameters in patients with ARSACS and SPG7. These findings indicate involvement of the corneal subbasal nerve plexus and support the potential role of corneal confocal microscopy as a non-invasive ocular imaging modality for evaluating peripheral neural alterations in hereditary spastic ataxias.

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Social functioning in Primary Ciliary Dyskinesia (PCD): a study of lived experience, relationships and support of patients and caregivers

Fernandez-Rodriguez, A.; Karavasiloglou, N.; Gkatzou, V.; Dexter, K.; Manion, M.; Silberschmidt, H.; Zambrano, S. C.; Pagnini, F.; Kuehni, C. E.; Goutaki, M.

2026-08-27 epidemiology 10.64898/2026.08.24.26360722 medRxiv
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Primary ciliary dyskinesia (PCD) is a rare, genetic, multiorgan disease requiring lifelong management. Although PCD affects everyday life, little is known about how people with PCD experience social functioning (SF). We conducted a study within the international participatory Living with PCD study to comprehensively explore SF. First, we conducted a focus group and two semi-structured interviews with adults and parents of people with PCD. We analysed qualitative data thematically and used the findings to develop a multilingual online questionnaire on SF. The questionnaire was completed by 277 participants: 225 adults and adolescents with PCD (81%) and 52 parents of children with PCD (19%). Participants reported active social lives and strong close relationships. PCD had a positive impact on family relationships for 39% of adult/adolescent participants and 41% of parents reporting for children. Among adult/adolescent participants, 49% reported positive or no impact on romantic/intimate relationships, while 17% had avoided or ended a relationship because of PCD. PCD affected the ability to meet responsibilities for 54% of participants, free time for 58%, and planning effort for 53%. Participants were more comfortable discussing PCD with family, friends, and partners than in work or educational settings, where only 29% reported receiving support. Financial support, flexible work, or educational policies and better-trained healthcare professionals were the most frequently identified unmet needs. This study suggests that maintaining SF with PCD requires substantial individual and relational work. Improving SF for people with PCD requires systemic responses in healthcare, education, and employment, alongside support from close networks.

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Exploring Potential Minocycline-ARH3 Interactions in ADPRHL2-Associated CONDSIAS: A Translational Clinical and Computational Study

Barazandeh Shirvan, B.; Nejabat, M.; Hadizadeh, F.; Ashrafzadeh, F.; Ahangari, N.; Tavassoli, A.; Houlden, H.; Biglari, S.; Doosti, M.; Akhondian, J.; Hashemi, N.; Shekari, S.; Mohammadi, M.; Ashrafi, M. R.; Badv, R. S.; Heidari, M.; Ebrahimzadeh, F.; Rezaei, Z.; Lashgari Kalat, H.; Jafari, Z.; Pourbakhtiaran, E.; Nejad Shahrokh Abadi, R.; Ghayoor Karimiani, E.; Beiraghi Toosi, M.

2026-07-10 neurology 10.64898/2026.07.09.26357651 medRxiv
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Background: Stress-induced childhood-onset neurodegeneration with variable ataxia and seizures (CONDSIAS) is a rare autosomal recessive disorder caused by biallelic variants in ADPRHL2, which encodes ADP-ribosylhydrolase 3 (ARH3), a key enzyme involved in poly (ADP-ribose) (PAR) metabolism. Although Minocycline has been reported to attenuate PAR-mediated neurotoxicity primarily through modulation of PARP-dependent pathways, whether it may also interact with ARH3 or influence the structural behavior of pathogenic ARH3 variants remains unknown. This study was designed to explore this possibility by integrating clinical observation with computational structural analyses. Methods: Comprehensive clinical evaluation, targeted Sanger sequencing, and in silico pathogenicity analyses were performed. Protein modeling, molecular docking, and 100-ns molecular dynamics simulations were conducted to evaluate the predicted structural consequences of the p.Thr79Pro variant and to explore potential interactions between ARH3 and Minocycline. Results: A homozygous ADPRHL2 variant (NM_017825.3:c.235A>C; p.Thr79Pro) was identified in a child with CONDSIAS. Computational analyses predicted reduced structural stability and increased conformational flexibility of the mutant ARH3 protein relative to the wild-type structure. MM-GBSA calculations estimated differences in binding free energies between the wild-type (-34.51 kcal/mol) and mutant (-39.76 kcal/mol) ARH3-Minocycline complexes, suggesting subtle differences in their predicted energetic profiles. Clinically, neurological progression appeared stable, with improved motor function observed during approximately one year of follow-up and no notable treatment-related adverse effects. Conclusions: By integrating clinical observations with computational structural analyses, this study provides preliminary computational support for the hypothesis that Minocycline may influence ARH3 conformational behavior in addition to its proposed effects on PARP-dependent pathways. Although these findings do not demonstrate direct molecular binding or therapeutic efficacy, they provide a biologically plausible framework for future biochemical, cellular, and functional investigations. Keywords: CONDSIAS; ADPRHL2; ARH3; Minocycline; molecular docking; molecular dynamics simulation; structural bioinformatics; translational medicine