Results of May 12th Usher Conference Part I: The Screening Conundrum

May 13, 2009

By Mark Dunning

The Usher conference was held in the New Research Building at Harvard Medical School. It is a very interesting building with it's molecule art, chromosome bathroom signs (XY for guys), and petri dish laden metal carts plying the hallways. You could definitely feel the science in the air.

The meeting was attended by a dozen researchers and a couple of observers. The goal of the meeting was to try to support the many upcoming clinical trials on Usher syndrome. The greatest problems facing these trials is the lack of appropriate candidates for the trials and our lack of an understanding of the natural history of the different types of Usher. We were attempting to find ways to remedy those problems.

There was a lot of excitement around upcoming treatment trials. There are gene therapy trials in the works for Usher types 1b, 1c, and 3. Clinical trials on stem cell treatments for Usher 2a and drug therapies for Usher 1f were also discussed. The drug therapies have the potential to help many Usher patients regardless of type provided they have a nonsense mutations.

The meeting bogged down in the details of finding Usher patients and tracking their histories. These efforts face several major hurdles:

1. Any multi-center natural history study will cost a lot of money.
2. NIH has shown a reluctance to fund such studies, meaning we would have to find the funding elsewhere or modify our approach.
3. The different institutions interested in joining the study all gather different data and store it in different formats. So some institutions use OCT some use Dark Adaptive Testing but they may or may not do both. The patient data would then be incompatible with only OCT data on patient 1 and only DAT data on patient 2.
4. Privacy laws prohibit researchers from sharing raw data, or even discussing the nature of an indivduals data, without the consent of that individual. That makes creating any sort of single database difficult to create.

We also face a chicken and egg problem when it comes to identifying Usher patients. The only sure way to identify them is through genetic testing. However, we can't test everyone. There has to be some sort of screening process to identify possible Usher patients.

For infants with Usher Type 1, those markers are hearing loss and poor balance. It is very difficult to identify Usher Type 2 or 3 at a young age, though, because we simply do not have enough natural history information to know what to look for. Hence the chicken and egg problem: We have don't know how to identify a child with Usher type 2 at a young age because we haven't identified many children with Usher type 2 at a young age.

Sticky problems indeed. I'll have more on the conference over the next couple of days. Stay tuned.