Goal attainment in PMM2-CDG: A new approach measuring meaningful clinical outcomes

Patient-centered outcomes, including patient-reported outcomes (PROs), are increasingly important in healthcare and research, though their use in rare diseases remains limited. In disorders with significant phenotypic variation, selecting appropriate outcome measures is crucial to ensuring the relevance of clinical trials for the patient population. Phosphomannomutase 2-CDG (PMM2-CDG) involves a complex genotype-phenotype relationship, making it challenging to predict clinical outcomes and select reliable measures for clinical trials. Caused by biallelic pathogenic variants in the PMM2, PMM2-CDG displays highly variable clinical severity, underscoring the need for personalized outcome measures. One such so far unexplored, individualized approach is Goal Attainment Scaling (GAS), which allows patients to set and track personal goals over time. We evaluated 93 PMM2-CDG patients enrolled in the Frontiers in Congenital Disorders of Glycosylation Consortium (FCDGC) Natural History study, classifying patient goals using the International Classification of Functioning, Disability, and Health (ICF) model, and assessing goal achievement prospectively.