[The Usher Syndrome, a Human Ciliopathy]

Area of Science:

• Genetics and Ophthalmology
• Rare Diseases Research

Background:

• Usher syndrome (USH) is a rare genetic disorder leading to inherited deaf-blindness.
• Clinical manifestations vary, categorized into three types (USH1-3) based on severity.
• Accurate diagnosis requires auditory, ophthalmological, and molecular genetic assessments.

Purpose of the Study:

• To elucidate the role of USH proteins in the sensory cells of the eye and ear.
• To review diagnostic approaches and therapeutic strategies for Usher syndrome.
• To discuss the limitations of current animal models for ophthalmic USH research.

Main Methods:

• Analysis of USH gene functions in hair cells and photoreceptor cells.
• Review of diagnostic criteria including genetic testing.
• Evaluation of preclinical and clinical gene therapy approaches.

Main Results:

• USH proteins form essential networks in auditory hair cells and visual photoreceptor cells.
• Specific USH protein functions include hair bundle differentiation, mechano-electrical transduction, and intracellular transport.
• Mouse models are inadequate for studying the visual aspects of USH due to anatomical differences.

Conclusions:

• Understanding USH protein networks is key to addressing the complex pathology of Usher syndrome.
• Gene therapy, including gene addition and nonsense mutation readthrough, shows promise for treating USH.
• Targeted therapies for the visual impairment in USH are still under development, with ongoing clinical trials.