Rigorous genetic diagnosis review in natural history studies

BACKGROUND: Leukodystrophies are a clinically and genetically heterogeneous group of diseases characterized by white matter abnormalities on brain magnetic resonance imaging. Clinical, biochemical, molecular, and/or neuroimaging findings collectively support the diagnosis confirmation. The heterogeneous and overlapping clinical presentations of different leukodystrophies and non-diagnostic molecular testing pose a significant challenge to establishing a definitive diagnosis in these rare diseases. The Myelin Disorders Biorepository Project is an observational research program that aims to establish new tests to diagnose leukodystrophies and describe the natural history of these disorders. Ensuring an accurate diagnosis is critical to the goals of this project, and this paper aims to describe the rigorous diagnostic review and confirmation process which was developed. RESULTS: We present a diagnosis review process that contributes to an accurate diagnosis for participants enrolled in this study. Board-certified genetic counselors with expertise in these disorders audit medical records to carefully assess each enrolled participant's clinical, biochemical, and molecular features. A scale of diagnostic categories is assigned based on the record review, and a team of leukodystrophy physician experts consults for cases that require further characterization or clarification. CONCLUSIONS: This robust review process has resulted in a database of individuals with verified diagnoses that may be easily queried for inclusion in appropriate natural history studies and/or treatment trials. This is a model framework that may be adapted and implemented by other rare disease groups.