Each month, we share summaries of recent Rare Diseases Clinical Research Network (RDCRN) grant-funded publications. Catch up on the latest RDCRN research below and listen to these summaries on the Rare Research Report podcast.
Global Leukodystrophy Initiative Clinical Trials Network (GLIA-CTN)
Developing a New Process to Improve Diagnostic Accuracy in Leukodystrophies
Leukodystrophies are a complex, often progressive group of disorders affecting the white matter of the brain due to the loss or absence of myelin, the protective coating around nerves. Different leukodystrophies can have many different genetic variants and symptoms, making them difficult to diagnose.
In this study, researchers developed a new process to improve diagnostic accuracy in leukodystrophies. First, genetic counselors with expertise in leukodystrophies review participants’ medical records, assessing the clinical, biochemical, and molecular features. Next, the team assigns diagnostic categories based on the record review. Finally, leukodystrophy physician experts consult for cases that need additional characterization or clarification.
The process has resulted in a large database of individuals with verified leukodystrophy diagnoses, improving identification of patients that can participate in natural history studies and treatment trials. Authors note that this process can also be used by other rare disease groups.
Pizzino A, Arnold K, Wiener E, Muirhead K, Schmidt J, Dominguez-Gonzalez CA, Banglorewala P, Fraser JL, Ruzhnikov M, Cohen JS, Sherbini O, Logan R, Gavazzi F, Sevagamoorthy A, Vincent A, D'Aiello R, Vanderver A. Rigorous genetic diagnosis review in natural history studies. Orphanet J Rare Dis. 2026 Apr 28;21(1):182. doi: 10.1186/s13023-026-04317-2. PMID: 42050713; PMCID: PMC13154562.
Measuring Function in Children with Leukodystrophy
Leukodystrophies are a complex, often progressive group of disorders affecting the white matter of the brain due to the loss or absence of myelin, the protective coating around nerves. Although all leukodystrophies affect neurological function, the severity and speed of progression can be very different among different types.
In this study, researchers evaluated a tool to measure function in children with leukodystrophy. Ninety-nine caregivers completed four domains (daily activities, mobility, social/cognitive, and responsibility) of a parent-reported assessment called the Pediatric Evaluation of Disability Index-Computer Adapted Test (PEDI-CAT). Researchers compared the results of the daily activities and mobility domains with clinician-administered assessments, including grasp and visual motor integrations subtests, of the Peabody Developmental Motor Scale (PDMS-2) and the 88-item Gross Motor Function Measure (GMFM-88).
Results showed a strong agreement between the PEDI-CAT and the above standard assessments. This suggests that the PEDI-CAT is a reliable way to measure functional abilities in leukodystrophy, especially when clinician-administered assessments are not possible. The authors note that the PEDI-CAT is a potentially critical tool for leukodystrophy families to be able to participate in research remotely.
Cusack SV, Glanzman AM, Gavazzi F, Woidill S, Jawad AF, Estilow T, Waldman AT, Vanderver A, Adang L; Children's Hospital of Philadelphia Leukodystrophy Workgroup. Performance outcomes of the PEDI-CAT for assessing functional ability in the population with leukodystrophy. Dev Med Child Neurol. 2026 Apr 30. doi: 10.1111/dmcn.70299. Epub ahead of print. PMID: 42060827.
The Rare Diseases Clinical Research Network (RDCRN) is funded by the National Institutes of Health (NIH) and led by the National Center for Advancing Translational Sciences (NCATS) through its Division of Rare Diseases Research Innovation (DRDRI). Now in its fifth five-year funding cycle, RDCRN is a partnership with funding and programmatic support provided by Institutes, Centers, and Offices across NIH, including the National Institute of Neurological Disorders and Stroke, the National Institute of Allergy and Infectious Diseases, the National Institute of Diabetes and Digestive and Kidney Diseases, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the National Institute of Arthritis and Musculoskeletal and Skin Diseases, the National Heart, Lung, and Blood Institute, the National Institute of Dental and Craniofacial Research, the National Institute of Mental Health, the Office of Dietary Supplements, the National Institute on Aging, the National Human Genome Research Institute, the National Institute on Deafness and Other Communication Disorders, and the Office of Research on Women’s Health.
