Mucopolysaccharidosis III B: A Case Report

Introduction Mucopolysaccharidosis type III B (MPS III B) is a rare, autosomal recessive disorder with a broad constellation of progressive symptoms. The time course and onset of disease can vary broadly. Case Presentation We present a case following a male from birth to age eight years in his development of disease with MPS III B. Macrocephaly and developmental delay began at 10 months, followed by sensorineural hearing loss. Urine mucopolysaccharide screen was diagnostic for MPS III B, and development was temporarily stabilized with varied supportive therapy. Discussion Early MPS III B diagnosis remains challenging despite variable presentations. This case emphasizes the importance of clinical suspicion, supportive therapy benefits, and the need for improved screening methods and developmental monitoring. Conclusions This case demonstrates the value of newborn screening, awareness amongst clinicians, and continued support for treatment development. MPS III B can present in broadly different time courses and therefore, is important to consider in differentials.