Featured Video: Jason's Changes Over Time & Exam with Dr. Pastores

Mucopolysaccharidosis type II (MPS II), also known as Hunter syndrome, is a rare inherited lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase, an enzyme that helps cells break down complex sugars. Without it, these complex sugars (glycosaminoglycans) accumulate, damaging multiple organs throughout the body. It’s passed down on the X chromosome, so it mostly affects boys, with signs often starting in early childhood. Common features include coarse facial traits, frequent ear and airway problems, an enlarged liver and spleen, stiff joints, heart issues, and hearing loss; some children also develop learning and behavior difficulties. Treatment includes regular enzyme infusions and supportive care to manage complications. It’s estimated to occur in roughly 1 out of every 100,000–170,000 male births.

In 2008, GeneticaLens filmed a documentary about MPS II, which provided an in-depth look into the signs, symptoms, and treatments of MPS II, and followed the lives of several individuals diagnosed with the condition.

In this excerpt from the documentary, we see Jason as he looks back over photos from his childhood that show his development. We also see him go to an appointment with Dr. Gregory Pastores, an expert in MPS II.