Longitudinal Natural History of Pediatric Subjects Affected with Mucopolysaccharidosis IIIB

Okur İ., Ezgu F. S., Giugliani R., Muschol N., Koehn A., Amartino H., ...More

Journal of Pediatrics, vol.249, pp.50, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Abstract
  • Volume: 249
  • Publication Date: 2022
  • Doi Number: 10.1016/j.jpeds.2022.06.005
  • Journal Name: Journal of Pediatrics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, CAB Abstracts, CINAHL, EMBASE, MEDLINE, Veterinary Science Database
  • Page Numbers: pp.50
  • Keywords: adaptive behavior, cognition, natural history, organ MRI, Sanfilippo syndrome Type III
  • Gazi University Affiliated: Yes


© 2022 The Author(s)Objective: To characterize the longitudinal natural history of disease progression in pediatric subjects affected with mucopolysaccharidosis (MPS) IIIB. Study design: Sixty-five children with a confirmed diagnosis of MPS IIIB were enrolled into 1 of 2 natural history studies and followed for up to 4 years. Cognitive and adaptive behavior functions were analyzed in all subjects, and volumetric magnetic resonance imaging analysis of liver, spleen, and brain, as well as levels of heparan sulfate (HS) and heparan sulfate nonreducing ends (HS-NRE), were measured in a subset of subjects. Results: The majority of subjects with MPS IIIB achieved an apex on both cognition and adaptive behavior age equivalent scales between age 3 and 6 years. Development quotients for both cognition and adaptive behavior follow a linear trajectory by which subjects reach a nadir with a score <25 for an age equivalent of 24 months by age 8 years on average and by 13.5 years at the latest. All tested subjects (n = 22) had HS and HS-NRE levels above the normal range in cerebrospinal fluid and plasma, along with signs of hepatomegaly. Subjects lost an average of 26 mL of brain volume (−2.7%) over 48 weeks, owing entirely to a loss of cortical gray matter (32 mL; −6.5%). Conclusions: MPS IIIB exists along a continuum based on cognitive decline and cortical gray matter atrophy. Although a few individuals with MPS IIIB have an attenuated phenotype, the majority follow predicted trajectories for both cognition and adaptive behavior. Trial registration: ClinicalTrials.gov identifiers NCT02493998, NCT03227042, and NCT02754076.