A Long-term Follow-up Study of Patients With MPS IIIB From Gene Therapy Clinical Trials Involving the Administration of ABO-101 (rAAV9.CMV.hNAGLU)

This is a multicenter, non-interventional, long-term follow-up (LTFU) study in participants who have been treated with ABO-101 in a prior trial. Eligible participants will undergo clinical evaluations at prespecified intervals for 3 years from the last visit in the prior clinical trial (up to 5 years post-treatment).