Analysis of cognitive ability and adaptive behavior assessment tools used in an observational study of patients with mucopolysaccharidosis II

• Published in: Orphanet journal of rare diseases 2021-12, Vol.16 (1), p.501-501, Article 501
• Main Authors: Yee, Karen S, Wu, Yanyu, Harrington, Magdalena, Waisbren, Susan E
• Format: Article
• Language: English
• Subjects: Adaptability (Psychology); Adaptation, Psychological; Adaptive behavior; Aged; Airway management; Behavior; Child; Child, Preschool; Children; Clinical medicine; Cognition; Cognition disorders; Cognitive ability; Cognitive Dysfunction; Complications and side effects; DAS-II; Enrollments; Enzymes; Fibroblasts; Genetic disorders; Hearing loss; HS-FOCUS; Humans; Lysosomal storage diseases; Medical research; Metabolic disorders; Mucopolysaccharidosis; Mucopolysaccharidosis II; Nervous system; Observational studies; Participation; Patients; Pediatric research; Pediatrics; Psychological aspects; Psychologists; Rare diseases; Risk factors; VABS-II
• ISSN: 1750-1172; 1750-1172
• DOI: 10.1186/s13023-021-02118-3

Mucopolysaccharidosis II (MPS II) is a rare lysosomal storage disease characterized by cognitive impairment in most patients. This post hoc analysis evaluated changes in cognitive function, adaptive behavior and functional outcomes in patients with neuronopathic MPS II over time. Fifty-five children with MPS II were enrolled in a 24-month observational study (NCT01822184). The Differential Ability Scales, second edition (DAS-II; early years battery for ages 2 years 6 months to 6 years 11 months, school age battery for ages 7 years to 17 years 11 months), Vineland Adaptive Behavior Scales, second edition (VABS-II) and the Hunter Syndrome-Functional Outcomes for Clinical Understanding Scale (HS-FOCUS) were performed at baseline and 3-month intervals over 2 years. A subgroup of 38 children with a DAS-II General Conceptual Ability (GCA) score of 55-85 (below average-very low abilities) at any time during the study were included in this analysis. Mean (standard deviation [SD]) early years DAS-II GCA score decreased from 73.4 (15.7, n = 22) at baseline to 62.7 (34.9, n = 6) at month 24. For the six patients with early years GCA assessments at baseline and month 24, mean (SD) GCA scores decreased from 72.3 (21.3) at baseline to 62.7 (34.9) at month 24. School age GCA scores were stable over 2 years: mean (SD) 72.4 (11.8, n = 10) at baseline; 74.3 (12.3, n = 8) at month 24. Mean (SD) VABS-II Adaptive Behavior Composite (ABC) scores were stable throughout the study (baseline, 81.8 [11.8, n = 36]; month 24, 81.0 [10.2, n = 13]). Some associations between items and domains of HS-FOCUS (p