A child with Hunter Syndrome

Hunter syndrome is devastating. It’s caused by a single enzyme, IDS, that is either missing or malfunctioning. Without the enzyme the body is unable to break down complex sugar molecules and as those build up they cause permanent, progressive damage to the body and brain and, in some instances, result in severe mental disabilities. There is no cure and existing treatments are limited and expensive.

But now researchers at the University of Manchester in England have developed an approach that could help children – the vast majority of them boys – suffering from Hunter syndrome.

Working with a mouse model of the disease the researchers took some blood stem cells from the bone marrow and genetically re-engineered them to correct the mutation that caused the problem. They also added a “tag” to the IDS enzyme to help it more readily cross the blood brain barrier and deliver the therapy directly to the brain.

In a news release Brian Bigger, the lead researcher of the study published in EMBO Molecular Medicine, said the combination therapy helped correct bone, joint and brain disease in the mice.

“We expected the stem cell gene therapy approach to deliver IDS enzyme to the brain, as we have shown previously for another disease: Sanfilippo types A and B, but we were really surprised to discover how much better the tag made the therapy in the brain. It turns out that the tag didn’t only improve enzyme uptake across the blood brain barrier, but also improved uptake of the enzyme into cells and it appeared to be more stable in the bloodstream – all improvements on current technology.”

While the results are very encouraging it is important to remember the experiment was done in mice. So, the next step is to see if this might also work in people.

Joshua Davies has made a video highlighting the impact Hunter syndrome has on families: it’s called ‘Living Beyond Hope’