Exploration Into Lived Experiences of Multiple Sulfatase Deficiency-Affected Individuals and Their Families.

Despite their importance, rare diseases' impact on patients and families is understudied. This is particularly true for ultrarare disorders, such as multiple sulfatase deficiency (MSD), a pediatric neurodegenerative disorder. To address this gap, we captured caregiver perspectives on how multiple sulfatase deficiency affects their child, themselves, and their families regarding adaptive behaviors and health-related quality of life.Overall, 19 multiple sulfatase deficiency caregivers participated in assessments capturing health outcomes related to daily functional abilities (Vineland Adaptive Behavior Scale-Third Edition [VABS-3]: n = 19), child health-related quality of life (Caregiver Priorities and Child Health Index of Life with Disabilities: n = 12; Pediatric Quality of Life Inventory-generic core scales: n = 13), and caregiver health-related quality of life (Pediatric Quality of Life Inventory-family impact module: n = 12; Traumatic Brain Injury Caregiver Quality of Life: n = 15). The Pediatric Quality of Life Inventory-family impact module results were compared to a data set from metachromatic leukodystrophy (n = 30), a rare disease with an overlapping sulfatase deficiency.The Vineland Adaptive Behavior Scale-Third Edition captured global impairment across domains in multiple sulfatase deficiency. Despite these functional limitations, the Caregiver Priorities and Child Health Index of Life with Disabilities and Pediatric Quality of Life Inventory-generic core scales captured relative preservation of health-related quality of life, especially related to emotional well-being. Compared with the Pediatric Quality of Life Inventory-generic core scales, the Caregiver Priorities and Child Health Index of Life with Disabilities captured a broader spectrum of health-related quality of life across all domains and caregivers' top priorities in disease management and care coordination. The health-related quality of life of caregivers was severely impacted, with caregivers reporting profound feelings of grief and entrapment. Additionally, there was a similar caregiver burden between multiple sulfatase deficiency and metachromatic leukodystrophy.Our results will help inform psychosocial outcome measures for rare disease families and patient-centered endpoints in impending multiple sulfatase deficiency clinical trials.