natural history study of participants with sanfilippo syndrome type iiic

Conditions: Sanfilippo Syndrome Type C

Summary: this study is planned to document, through retrospective and prospective data collection, syndrome progression in children and young adults with mps iiic.

this is a multi-center, natural history study of subjects with sanfilippo syndrome type c or mps iiic. this study will combine a retrospective review of medical records and an ongoing collection of clinical data on an observational basis. real-world data will be collected at home using a recording device. participants will be asked to attend clinic visits in person on a yearly basis. in clinic visits will include neurocognitive, developmental, behavioral, biochemical, imaging measures as well as retrospective medical record analysis. at 6-month intervals between clinic visits, participants will be contacted remotely for some safety assessments (e.g., collecting information about concomitant medications, concurrent illnesses, and procedure-related adverse events \[aes\] and serious aes \[saes\] since last clinic visit). at 6-month intervals, caregivers will complete questionnaires and record home video assessments using a dedicated, compliant study application (app) called c-rare (recording application for real-world evidence). the c-rare app consists of 9 tasks of activities of daily living and socialization as well as three parent reported sanfilippo specific questionnaires. the objectives of this study are: * to enhance the understanding of the natural history and progression of mps iiic syndrome on behavior, cognitive abilities, mobility, vision, hearing, speech, and expressive and receptive language * to define and categorize clinical endpoints that may be used in future clinical trials

Eligibility criteria:
inclusion criteria: confirmed diagnosis of sanfilippo syndrome type c disease by all of the following: * deficiency in heparan-alpha-glucosaminide n-acetyltransferase enzyme activity * has presented with signs/symptoms consistent with sanfilippo syndrome type c, or, for individuals who have not presented with signs/symptoms of disease (eg, siblings of known patients), the determination of eligibility will be at the discretion of the sponsor in conjunction with the site investigator * genomic dna analysis demonstrating homozygous or compound heterozygous, pathogenic and/or potentially pathogenic variants in the hgsnat gene * accumulated gag hs in urine * written informed consent from parent or legal guardian and assent from patient, if required * parent/legal guardian willing to accompany the patient to all study visits * ability to comply with protocol requirements, in the opinion of the investigator * negative urine pregnancy test at screening (nonsterile females of childbearing potential only). functional abilities: * able to take food or liquid by mouth, able to walk with or without assistance. * has an age equivalent on the vineland adaptive behavior scales (vabs) of ≥1 year. exclusion criteria: patients who meet any of the following criteria will not be eligible to participate in the study: * have received an investigational drug within 30 days prior to the baseline visit * concomitant illness or medical condition or extenuating circumstance that, in the opinion of the investigator, might compromise the patient's ability to comply with protocol requirements, the patient's well-being or safety, or the interpretability of the patient's clinical data * the presence of significant non-mps iiic-related cns impairment or behavioral disturbances that would confound the scientific rigor or interpretation of results of the study

Keywords: sanfilippo syndrome type c mucopolysaccharidosis type iii c mps iiic