Data Sharing Experience, Guidance, and Resources From the Rare Diseases Clinical Research Network (RDCRN).

The Rare Diseases Clinical Research Network (RDCRN) comprises research consortia and other partners focused on the study of rare diseases. Its goals include sharing de-identified data with the scientific community and other stakeholders to advance rare disease research. The RDCRN Data Use & Data Sharing Committee and RDCRN Data Management and Coordinating Center reviewed data sharing practices across established consortia and published literature to develop guidance documents.

Clinically Important Endpoints in Individuals With Leukodystrophy: A Multisite Study.

Importance: Leukodystrophies are a diverse group of rare disorders that disrupt central myelination. These disorders present with a broad spectrum of neurologic severity and are associated with a range of potential secondary complications, such as scoliosis and failure of independent feeding.

Objective: we explore real-world data of leukodystrophy complications to inform future evidence-based care guidelines across these rare diseases.

The impact of vanishing white matter on unaffected family members.

Background: Vanishing White matter (VWM) is one of the more prevalent leukodystrophies, caused by biallelic pathogenic variants in any of the EIF2B1-5 genes. It is characterized by chronic progressive neurological deterioration and additional stress-provoked episodes of rapid decline, leading to severe neurological impairment and early death. The impact of VWM on unaffected family members has not been investigated.

Clinical Characterization of a Multicenter International Cohort of Patients With Aicardi-Goutières Syndrome Homozygous for the RNASEH2B:p.Ala177Thr Variant: Early Clinical Markers of Disease Severity.

Background: Aicardi-Goutières syndrome (AGS) is a rare monogenic leukodystrophy belonging to type I interferonopathies caused by alterations in one of nine genes. Among them, homozygous RNASEH2B:c.529G>A(p.

variants cause lysosomal and autophagic defects resulting in a hypomyelinating leukodystrophy with epileptic encephalopathy.

encodes a subunit shared by the BLOC-1 and BORC hetero-octameric complexes that regulate various endolysosomal processes. Here, we report the identification of seven distinct variants in in eleven individuals from seven independent families presenting with early psychomotor delay, hypotonia, spasticity, epileptic encephalopathy, optic atrophy, and leuko-axonopathy with hypomyelination. A subset of the affected individuals also have features of hypopigmentation and ocular albinism that are similar, although milder, than those of individuals with BLOC-1-related Hermansky-Pudlak syndrome.

Comprehensive genotype-phenotype analysis in POLR3-related disorders.

RNA polymerase III (RNA Pol III)-related disorders (POLR3-RDs) are a group of clinical entities characterized by causal variants in genes encoding RNA Pol III subunits, including POLR3A, POLR3B, POLR1C, POLR1D, POLR3D, POLR3E, POLR3F, POLR3GL, POLR3H, and POLR3K. These typically cause developmental phenotypes affecting the central nervous system; the eyes; connective tissues including bones, teeth, and endocrine axes; and the reproductive system. Similar phenotypes can be caused by variants in separate subunit genes (multigenic).

Experiences and Hope in Caregivers of Children With Aicardi Goutières Syndrome.

Aicardi Goutières syndrome is a type I interferonopathy that results in a spectrum of neurologic impairment. In general, neurodegenerative disorders of childhood strongly affect the quality of life and perspective of the whole caregiver network. This article aims to define the impact of Aicardi Goutières syndrome on affected individuals and families through a multimethod approach using quality of life surveys and qualitative interviews.

Single Large-Scale Mitochondrial Deletion Syndromes: Neuroimaging Phenotypes and Longitudinal Progression in Pediatric Patients.

Background And Purpose: Single large-scale mitochondrial deletion syndrome (SLSMD) comprises devastating mitochondrial diseases often classified into 3 major clinical syndromes: Kearns-Sayre syndrome (KSS), chronic progressive external ophthalmoplegia (CPEO), and Pearson syndrome (PS). Nevertheless, there remains large clinical variability and overlap among these SLSMD groups. Therefore, further stratification is required for more precise prognostication and clinical management.

Multiple molecular diagnoses identified through genome sequencing in individuals with suspected rare disease.

Genome sequencing is a powerful and comprehensive test that detects multiple variants of different types. The interrogation of variants across the genome enables the identification of multiple molecular diagnoses (MMDs) in a single individual. In this retrospective study, we describe individuals in whom MMDs were associated with the proband's indication for testing (IFT), secondary findings, or incidental findings.

Tofacitinib treatment for psoriatic skin lesions associated with Aicardi-Goutières syndrome 7/Singleton-Merten syndrome 1.

The purpose of this letter to the editor is to illustrate the effect of tofacitinib on psoriatic skin lesions in a patient with Aicardi-Goutières syndrome (AGS) type 7/Singleton-Merten syndrome 1. AGS is characterized by an encephalopathy of variable severity and systemic autoinflammatory manifestations due to continuous type I interferon (IFN) induction. While traditional JAK 1/2 inhibitors like baricitinib and ruxolitinib have proven effectiveness for systemic inflammatory symptoms, they face reimbursement issues in some countries.

Effective gene therapy for metachromatic leukodystrophy achieved with minimal lentiviral genomic integrations.

Metachromatic leukodystrophy (MLD) is a fatal lysosomal storage disease characterized by the deficient enzymatic activity of arylsulfatase A (ARSA). Combined autologous hematopoietic stem cell transplantion (HSCT) with lentiviral (LV)-based gene therapy has great potential to treat MLD. Achieving the optimal balance between high enzyme production for therapeutic efficacy and maintaining a low vector copy number (VCN) is crucial.

Using multiple modalities to confirm diagnosis in patients with suspected peroxisome biogenesis disorders.

Zellweger spectrum disorder (ZSD) results from biallelic variants in any one of 13 PEX genes involved in peroxisome biogenesis and function. The majority of ZSD cases result from pathogenic variants in PEX1. Here, we present 3 patients with suspected PEX1-related ZSD and non-diagnostic whole exome sequencing and describe the use of multiple modalities to ascertain their diagnosis.

POLR3-Related Leukodystrophy: A Qualitative Study on Parents' Experiences With the Health Care System.

Background: POLR3-related hypomyelinating leukodystrophy (POLR3-HLD) is a rare, inherited neurodegenerative disorder affecting white matter development of the central nervous system. This disorder is characterized by hypomyelination, hypodontia, and hypogonadotropic hypogonadism (4H leukodystrophy). Patients with POLR3-HLD require complex and specialized care; however, due to its rarity and limited awareness, parents often assume additional roles as experts and advocates for their child(ren).

The natural history of variable subtypes in pediatric-onset TUBB4A-related leukodystrophy.

We establish the natural history of pediatric-onset TUBB4A-related leukodystrophy to improve clinical trial readiness through a medical record-based longitudinal study. An international cohort of 216 individuals with pediatric-onset TUBB4A-related leukodystrophy was included. Demographic information and medical events were extracted from medical records or publications.

Characterization of gallbladder disease in metachromatic leukodystrophy across the lifespan.

Metachromatic leukodystrophy (MLD) is a progressive demyelinating disorder resulting from the toxic accumulation of sulfatides. The stereotyped neurodegeneration of MLD is well understood, and cases are categorized into subtypes by age at neurologic onset: late infantile (LI), juvenile (J), and adult. The systemic burden of disease, such as gallbladder involvement, however, is less well characterized.

The prototypical interferonopathy: Aicardi-Goutières syndrome from bedside to bench.

Aicardi-Goutières syndrome (AGS) is a progressive genetic encephalopathy caused by pathogenic mutations in genes controlling cellular anti-viral responses and nucleic acid metabolism. The mutations initiate autoinflammatory processes in the brain and systemically that are triggered by chronic overproduction of type I interferon (IFN), including IFN-alpha. Emerging disease-directed therapies aim to dampen autoinflammation and block cellular responses to IFN production, creating an urgent and unmet need to understand better which cells, compartments, and mechanisms underlying disease pathogenesis.

Stress and Quality of Life of Parents of Children With POLR3-Related Leukodystrophy: A Cross-Sectional Pilot Study.

RNA polymerase III (POLR3)-related leukodystrophy is a rare, neurodegenerative disorder characterized by hypomyelination, hypodontia, and hypogonadotropic hypogonadism. Despite the challenges of caring for a child with POLR3-related leukodystrophy, few studies have examined parents' disease burden. We sought to investigate quality of life and stress levels amongst parents of children with POLR3-related leukodystrophy.

Practical Approach to Longitudinal Neurologic Care of Adults With X-Linked Adrenoleukodystrophy and Adrenomyeloneuropathy.

Although X-linked adrenoleukodystrophy (ALD) has historically been considered a childhood disease managed by pediatric neurologists, it is one of the most common leukodystrophies diagnosed in adulthood. An increase in both male and female adults reaching diagnosis due to familial cases identified by state newborn screening panels and more widespread use of genetic testing results in a large cohort of presymptomatic or early symptomatic adults. This population is in urgent need of standardized assessments and follow-up care.

Approaches to diagnosis for individuals with a suspected inherited white matter disorder.

Leukodystrophies are heritable disorders with white matter abnormalities observed on central nervous system magnetic resonance imaging. Pediatric leukodystrophies have long been known for their classically high, "unsolved" rate. Indeed, these disorders provide a diagnostic dilemma for many clinicians as over 100 genetic disorders alone may present with white matter abnormalities, with this figure not taking into account the substantial number of infectious agents, toxicities, and acquired disorders that may affect the white matter of the brain.

Glial Origins of Inherited White Matter Disorders.

Inherited white matter disorders (IWMDs) are a phenotypically and genotypically heterogeneous group of disorders affecting the central nervous system (CNS) with or without peripheral neuropathy. They are classified either as leukodystrophies (LDs), with primary glial abnormalities, or genetic leukoencephalopathies (gLEs), where other CNS cells are involved. As a group, these disorders are common, with an incidence of 1 in 7500 births.

Utility of genome sequencing in exome-negative pediatric patients with neurodevelopmental phenotypes.

Exome sequencing (ES) has emerged as an essential tool in the evaluation of neurodevelopmental disorders (NDD) of unknown etiology. Genome sequencing (GS) offers advantages over ES due to improved detection of structural, copy number, repeat number and non-coding variants. However, GS is less commonly utilized due to higher cost and more intense analysis.

Developmental delay can precede neurologic regression in early onset metachromatic leukodystrophy.

Objective: Metachromatic leukodystrophy (MLD) is a rare neurodegenerative disorder. Emerging therapies are most effective in the presymptomatic phase, and thus defining this window is critical. We hypothesize that early development delay may precede developmental plateau.