Orphanet Journal of Rare Diseases

Objective: To characterize the clinical, radiological, and pathological features of Neuro-Ocular Vasculopathy Associated with Fanconi Anemia (NOVA-FA). Methods: Six patients with FA and neurological symptoms were phenotyped using retrospective chart review of clinical notes, neuroimaging, fluorescein angiogram, CSF analysis, and advanced research techniques including extensive infectious testing. Biopsies were reviewed in two patients. Results: NOVA-FA is defined by neurological symptoms, retinal vasculopathy, accumulation of punctate cerebellar lesions and/or large mass-like lesions with surrounding vasogenic edema. Histopathology showed vasculopathy without inflammation. Treatments with immunosuppressants appeared largely ineffective. Imaging and pathology suggest a non-inflammatory small vessel vasculopathy as the primary pathology. Interpretation: NOVA-FA is a recently identified condition that affects a subset of patients with FA and results in significant disability, including death. The etiology remains unknown, although the condition mimics features of the syndrome retinal vasculopathy and cerebral leukodystrophy which is due to dysfunction in DNA repair mechanisms. There is currently no known effective treatment.

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.

Aims: To describe the developmental phenotype of individuals with STXBP1-related disorders (STXBP1-RD) in a prospective natural history study using standardized outcome measures. Methods: Data were collected from 155 individuals with a mean age of 8.2 years. The Bayley Scales of Infant and Toddler Development-Fourth Edition (Bayley-4), Hand Manipulation and Eye Hand Coordination subtests of the Peabody Developmental Motor Scales-Third Edition (PDMS-3), and Gross Motor Function Measure-66 (GMFM-66) were assessed. The Gross Motor Function Classification System (GMFCS), Mini-Manual Ability Classification System (MiniMACS), Manual Ability Classification System (MACS), and Communication Function Classification System (CFCS) were used to classify participants. Results: Assessments were well tolerated with 0-6.9% incomplete assessments. Floor or ceiling effects were not common with raw scores, age equivalents, or growth scales values but were frequently observed with scaled scores. Significant differences were found between the Bayley-4, GMFM-66, and PDMS-3 when participants were divided into groups by corresponding developmental domain classification scale. Strong associations (p < 0.05) were seen between all measures across Bayley-4 domains, PDMS-3 domains, and GMFM-66 total scores. Interpretation: The Bayley-4, GMFM-66, and PDMS-3 are suitable for use in clinical practice and future clinical trials in STXBP1-RD.

The Vanishing White Matter (VWM) Registry is a single-center database containing longitudinal survey data from >470 untreated patients with DNA- and MRI-confirmed VWM. VWM is a rare genetic disorder of the brain's white matter with an estimated live birth incidence of 1 per 100,000 and prevalence of 1.3 per 1,000,000 people in the Netherlands. The Registry represents a remarkably extensive collection of systematically gathered information on this disease, enabling crucial research into the natural history of VWM and providing a valuable resource for control arms in clinical trials. Data, initially collected on paper from 2004, have been maintained electronically since 2018, and include validated scales alongside a disease-specific customized questionnaire covering clinical, functional, and psychosocial domains. Survey packages, available in eight languages, are sent one to four times a year, depending on patient age. Built-in validity checks and review by pediatric and adult neurologists ensure data quality. The dataset is continuously updated with questionnaires expanding its scope, and structured for analysis and reuse in research on VWM.

ABSTRACT Introduction: Incomplete penetrance and variable expressivity characterize autosomal dominant neurological disorders, but their genetic determinants remain largely unknown. DYT-TOR1A dystonia provides a model for investigating incomplete penetrance. We aimed to identify modifiers of disease penetrance and severity beyond the known TOR1A c.646G>C modifier. Methods: In a prospective genotype-phenotype association study, we phenotyped Ashkenazi Jewish carriers of TOR1A c.907_909del using a prespecified five-level severity score. The primary analysis compared participants with no or minimal dystonia (scores 0-1) and severe dystonia (scores 3-4), after excluding c.646G>C carriers. Findings were assessed in an independent retrospective cohort. Sanger, exome, and short-read and long-read whole-genome sequencing were used for genotyping. Results: The prospective cohort included 61 carriers: 21 had severe dystonia and 28 had no or minimal dystonia, six of whom carried c.646G>C. Among the 43 participants in the primary analysis, haplotype A was identified in 33 (77%) and haplotype B in eight (19%). All haplotype B carriers had no or minimal dystonia (p=0.003). Haplotype B remained associated with a milder phenotype after including 12 participants with intermediate severity (p=0.006). The retrospective cohort included 147 carriers, 16 of whom carried c.646G>C. After their exclusion, dystonia manifested in 12 (38%) of 32 participants with haplotype B and 63 (64%) of 99 without it (p=0.009). Haplotype B was also associated with lower severity scores (p=0.011). Together, c.646G>C and local haplotype status predicted the phenotype of more than two-thirds of carriers. In silico analyses linked haplotype B to lower TOR1A and higher TOR1B expression in dystonia-relevant brain regions. Conclusion: A common local haplotype in trans to the disease-causing TOR1A variant was strongly associated with reduced penetrance and severity. These findings establish DYT-TOR1A dystonia as a model for investigating how local genetic variation contributes to incomplete penetrance in autosomal dominant neurological disorders.

Background Trimethylaminuria (TMAU) is a rare metabolic disorder characterized by malodor resulting from impaired metabolism of trimethylamine, but its broader impact on patients lives remains insufficiently characterized. This study aimed to assess the diagnostic, psychosocial, educational, occupational, and treatment-related burden of TMAU across a multinational patient population and to explore cognitive manifestations identified during the study. Methods We conducted a multinational, cross-sectional, patient-reported survey using an anonymous online questionnaire. Of 450 submissions, 401 participants provided valid authorization for analysis. The survey assessed demographic characteristics, symptom and diagnostic experiences, educational and occupational consequences, psychosocial burden, and perceptions of current management. Cognitive complaints emerging during the initial study prompted a follow-up survey focused on cognitive symptoms and their functional impact, completed by 306 participants from the original cohort. The association between cognitive symptom frequency and severity was assessed using Spearman rank correlation. Results Participants represented more than 40 countries, and 61.1% were female. A substantial diagnostic gap was observed, with 65.8% reporting no official diagnosis or clear medical explanation of probable TMAU. Social and psychological consequences were prominent, including physical rejection or social exclusion (78.8%), bullying or derogatory treatment (61.1%), and substantial disruption of educational and occupational participation. Most participants (84.3%) considered currently available treatment options insufficient. In the cognitive follow-up survey, 68.0% reported cognitive difficulties at least several times per week, 58.8% reported moderate or severe symptoms, and 66.7% reported at least moderate interference with daily activities, work, or studies. Greater cognitive symptom frequency was significantly associated with greater severity (Spearman coefficient = 0.451, p < 0.001). Conclusions TMAU is associated with a multidimensional patient-reported burden extending beyond malodor to psychosocial, educational, occupational, and previously underrecognized cognitive manifestations. These findings support earlier recognition, multidisciplinary care, and development of mechanism-based therapies evaluated using patient-centered outcomes that include daily functioning, cognitive symptoms, and quality of life.

Background and objectives: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is the most common monogenic cerebral small vessel disease. Though neuropsychiatric symptoms (NPS) of CADASIL profoundly impact function and quality of life, these symptoms remain understudied. This analysis characterizes the prevalence, severity, and profile of NPS among individuals with CADASIL-causing NOTCH3 variants and non-carrier biological family controls in the United States CADASIL Consortium (USCC). Methods: This cross-sectional analysis used multimodal baseline data from 12 enrollment sites across the country. Statistical analyses used nonparametric tests and regression models to compare clinical and neuropsychiatric outcomes across CADASIL risk tiers and controls, adjusting for age, sex, race, and education where appropriate. The primary outcome measure was the Neuropsychiatric Inventory Questionnaire (NPI-Q), an informant-reported measure which assesses 12 categories of NPS. NPI-Q item severity and distress were evaluated for individuals with confirmed cysteine-altering NOTCH3 variants and compared with controls. Results: Four hundred fifty-nine USCC participants were included in the analytic cohort: 343 cases [256 high-risk (HR); 63 medium-risk (MR); 24 low-risk (LR)]; and 116 controls. Among participants with available NPI-Q data, at least one neuropsychiatric symptom was reported by 72.6% (n = 228/314) of cases compared with 53.2% (n = 58/109) of controls. Reported symptoms were more common among CADASIL cases than controls, occurring in 75.0%, 71.2%, and 72.7% of participants in the LR, MR, and HR groups, respectively, compared with 53.2% of controls. Compared with controls, participants in the MR group and HR group had higher NPI-Q severity scores. HR participants also had higher NPI-Q distress scores than controls. Discussion: Our findings support the notion that NPS are an important clinical manifestation of CADASIL. Beyond previously reported symptoms, additional neuropsychiatric manifestations were identified. Given the higher burden and variability in the neuropsychiatric presentation of CADASIL, the relationships among neuropsychiatric, neurological, and patient-reported outcomes merit further investigation. The NPS profile may enhance the evaluation of the safety and efficacy of different treatments to target these symptoms for CADASIL patients. Trial Registration Information: The study is registered at ClinicalTrials.gov (NCT05677880, 12/12/2022).

Background: Hereditary spastic paraplegia (HSP) comprises a heterogeneous group of neurodegenerative disorders characterized by progressive lower-extremity weakness and spasticity, with or without additional neurological symptoms. Objectives: To characterize the molecular genetic spectrum, inheritance patterns, molecular finding rate, and clinical characteristics of HSP within a multicenter Canadian cohort. Methods: We investigated 671 patients from 423 families who met clinical criteria for HSP identified through the Canadian HSP (CanHSP) registry from 7 medical centers across Canada. Patients were evaluated using known HSP and HSP mimic gene panels, whereas unsolved and more recent patients underwent whole-exome sequencing (WES). 435 individuals underwent gene-panel testing and 485 underwent WES. Copy-number variants (CNVs) were assessed using ExomeDepth, and candidate CNVs using multiplex ligation-dependent probe amplification (MLPA). Results: Molecular findings were identified in 426 of 671 individuals (63.5%): 351 (52.3%) had HSP-associated findings, 70 (10.4%) HSP-mimicking disorders, and five (0.7%) other molecular findings; 245 (36.5%) remained unresolved. Candidate variants were found in 80 relevant genes, 36 of which were HSP-associated genes. The most frequently implicated genes were SPAST (22.5%), SPG7 (5.7%), ATL1 (5.2%), SPG11 (3.6%), and SPG8 (3.3%). Phenotypically, SPAST, ATL1, and SPG8 w[zg1.1]ere predominantly associated with pure HSP, whereas SPG7 and SPG11 more often showed complicated phenotypes, with prominent cerebellar involvement in SPG7 and cognitive and developmental features in SPG11. Conclusion: Patients in CanHSP present with genetic and phenotypic heterogeneity. Reanalysis and complementary approaches, including whole-genome, RNA, and long-read sequencing, may increase diagnostic yield.

Background: Rare genetic diseases collectively affect hundreds of millions of people, yet their clinical features are usually defined in small and selected patient groups which do not represent the entire population. The FMR1 CGG repeat expansion, one of the most common trinucleotide disorders, illustrates what we know about a genetic carrier's susceptibility that predisposes to multiple medical problems, which unfortunately remains poorly characterised. FMR1 premutation-associated conditions (FXPAC) encompass a spectrum of clinical manifestations. FMR1 premutation carriers are at risk of developing conditions such as fragile X-associated primary ovarian insufficiency (FXPOI), fragile X-associated tremor/ataxia syndrome (FXTAS), and a range of neuropsychiatric symptoms collectively termed Fragile X-associated neuropsychiatric disorders (FXAND), which to this date remain a topic of concern and debate. Despite an estimated carrier prevalence of 1 in 151 females and 1 in 468 males, FMR1 premutation carriers frequently remain undiagnosed or misdiagnosed. Electronic Health Records (EHRs) structured in the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM) enable large-scale retrospective phenotyping of such rare conditions. Methodology: Using OMOP-mapped EHR data from the Mount Sinai Health System, we identified a cohort of 750 individuals with a confirmed FMR1 premutation status (98.5% female; median age at index 33.3 years), to our knowledge the largest EHR-derived FMR1 premutation cohort described within a single health system to date. Results: Several key FXPAC-associated diagnoses were documented before formal FMR1 premutation identification: Endocrine/Metabolic (16.5%, n = 124/750) and Neuropsychiatric (16.3%, n = 122/750) conditions were the most prevalent FXPAC domains. In every domain a substantial share of patients had their first record before the index date: the first-quartile lead time was 1.9 years for FXAND (n = 122), 1.5 years for FXPOI (n = 64), 1.0 years for both pain/fatigue (n = 19) and autoimmune/inflammatory conditions (n = 15), and 0.1 years for endocrine/metabolic conditions (n = 124); only FXTAS (n = 13) showed no pre-index lead (Q1 = 0.0 years). These lags reveal a measurable diagnostic gap prior to the identification of the FMR1 premutation. This study demonstrates that large-scale EHR-based phenotyping can characterise the clinical burden of rare genetic conditions, quantify diagnostic delays at the population scale, and identify precursor diagnosis patterns that may support earlier genetic referral in clinical practice.

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.

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.

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.

Objective: Chronic atrial and intestinal dysrhythmia (CAID) syndrome is a rare autosomal recessive cohesinopathy classically defined by sick sinus syndrome and chronic intestinal pseudo-obstruction; however, emerging evidence suggests an association with cerebral small vessel disease (CSVD). We aimed to characterize the neurological and neuroimaging spectrum of CSVD in CAID syndrome. Methods: We conducted a cross-sectional, retrospective study of 16 French-Canadians with genetically confirmed CAID syndrome. All patients underwent comprehensive neurological assessment. Brain MRI was performed in 14 patients, with CSVD markers evaluated by an expert neuroradiologist according to the STRIVE-2 criteria. Results: The median age at last evaluation was 34 years (range, 19-60); 62.5% were women. Neurological manifestations included migraines (44.4%), mild cerebellar signs (16.7%), and ischemic or hemorrhagic cerebrovascular events (12.5%). MRI showed white matter hyperintensities (92.9%), lacunes (50%) and cerebral microbleeds (85.7%), affecting deep, lobar, and infratentorial regions, with marked cerebellar predominance (11/12; 91.7%); five patients exhibited innumerable microbleeds. Despite the young cohort, moderate-to-severe CSVD was common (median SVD score 1.5, IQR 0-4). Patients with countless microbleeds were older than those with discrete lesions (46.2 vs. 31.2 years; p=0.043). Management of atrial fibrillation required individualized strategies, including left atrial appendage closure, balancing ischemic and hemorrhagic risks. Interpretation: CAID syndrome represents a novel monogenic cause of CSVD, characterized by early, extensive cerebral microbleeds with mixed distribution and distinctive cerebellar predominance. Coexisting congenital cardiac disease and arrhythmias place patients at dual ischemic and hemorrhagic risk. Systematic neurological evaluation and MRI are warranted, particularly prior to antithrombotic therapy.

We report the generation and characterization of a human induced pluripotent stem cell (iPSC) line derived from dermal fibroblasts of a patient with Skogholt disease, a rare maternally inherited neurodegenerative syndrome associated with choroid plexus dysfunction and impaired cerebrospinal fluid (CSF) homeostasis. Patient fibroblasts were reprogrammed using the non-integrating Repro-OSKGM kit. The resulting iPSC line exhibited typical pluripotent morphology, expressed canonical pluripotency markers, maintained a normal karyotype, retained the disease-associated genetic variant, was mycoplasma-free, and demonstrated trilineage differentiation potential. We also made choroid plexus (ChP) like organoids from the generated iPSCs. This patient-specific iPSC line provides a valuable resource for generating choroid plexus organoids and neurons to investigate disease mechanisms and develop therapeutic strategies.

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.

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.

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.

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.

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.

Introduction The Brief Ataxia Rating Scale (BARS) and Scale for the Assessment and Rating of Ataxia (SARA) are used to quantify cerebellar ataxia severity. We investigated how often clinician ratings match patient reports of functional impairment, which scale items patients consider important, and whether incremental changes in item scores are meaningful to patients. Methods 30 patients with cerebellar ataxia completed BARS, SARA, FARS Functional Staging, and an Importance of Activities of Daily Living questionnaire. We studied BARS and SARA item scores for over- or underestimation in relation to patient perception of impairment. We explored patient rankings of item importance in relation to daily function, and their perception of the likely importance of 0.5- and 1-point changes in BARS gait and speech. Results Patients identified gait as most important on BARS and SARA, followed by oculomotor (BARS) and stance (SARA). Heel-to-shin was least important, with highest overestimation on both scales. Total overestimated points were similar between BARS (2.65 +/- 2.80) and SARA (2.78 +/- 2.78). 0.5-point changes in BARS gait and speech scores were rated very or extremely important by 60% and 46.6%, respectively, increasing to 83.3% and 70% for a 1-point change. Conclusion Gait is most meaningful to patients with cerebellar ataxia. BARS oculomotor and SARA stance rank second. BARS and SARA appendicular measures have limited patient-perceived clinical meaningfulness. 0.5-point increments in BARS gait and speech provide greater granularity of assessment and are considered meaningful by a substantial proportion of patients, supporting their relevance in practice and in clinical trials.