Tears May Hold the Key to Diagnosis and Treatment of Usher Syndrome

A groundbreaking pilot study at Radboudumc, co-funded by Usher Syndrome Ireland in collaboration with Stichting Ushersyndroom, has provided new insights into potential biomarkers for Usher syndrome type 1B (USH1B). Led by Dr. Irene Vázquez Domínguez, this research explored whether tiny cellular messengers found in tears and retinal pigment epithelial (RPE) cells could improve diagnosis and treatment monitoring for USH1B patients.
 

This research has provided important insights into how genetic errors in MYO7A can affect the body, and how small messages in cells and tears play a role in Usher syndrome. In particular, the unique RNA profiles in tears and RPE cells offer opportunities to better understand the disease and perhaps diagnose or treat it in the future.

Although the research has already provided promising insights, by Dr. Irene Vázquez Domínguez emphasises that larger cohorts are needed to validate the results. 

Key Findings:

• MYO7A mutations: Mutations in the MYO7A gene, primarily located in the MyTH4 domain, were identified. This domain plays a vital role in the protein’s function.
• Extracellular vesicles (EVs): RPE cells (cells in the retina that support photoreceptors) produce EVs that carry key messages. These packets are only produced on one side of the cell, the side facing the retina (apical)
• Normal cell development: Despite MYO7A mutations, RPE cells developed normally, and protein localisation remained intact.
• Small RNA differences: Small non-coding RNAs (sncRNAs) in EVs differed significantly between patients with Usher syndrome and healthy individuals, indicating their potential as diagnostic markers.
• Tears as a source: EVs in tears contained a broader range of sncRNAs than those from lab-cultured RPE cells. Tears may therefore serve as a more comprehensive source of diagnostic information.

Potential for future treatments: Validating tears as a source of biomarkers opens new possibilities for diagnostics and treatment. By understanding molecular mechanisms and specific sncRNAs, researchers could potentially develop therapies aimed at restoring normal retinal function.

What’s Next? The findings pave the way for larger studies to confirm these results and explore new treatment possibilities. Future research, supported by international collaboration and additional funding, will focus on further analysing RNA molecules and EVs in inherited retinal diseases.

You can read more about this study and learn what RPE cells here. 

Help us drive vital research forward! This is the first-ever Usher syndrome study funded by an Irish organisation, and with your support, we can continue making breakthroughs. Donate to Usher Syndrome Ireland today and be part of the journey toward improved understanding and treatments. Every contribution makes a difference!