USH1B is caused by mutations in the MYO7A gene. In the USA Alaa Koleilat is, under supervision of Dr Lisa Schimmenti (Mayo Clinic, USA), working on the development of a medicine for treating USH1B. She makes use of zebrafishes with mutations in the MYO7A gene, because this zebrafish model for USH1B shows serious deafness and balance problems. Because of their balance problems, these zebrafishes swim in circles. Apart from this, these USH1B zebrafishes do not react to sound stimuli. The hair cells of the USH1B zebrafishes no longer have a nice bundle of cilia, just like the hair cells of USH patients. It is expected that as a result of this the hair cells cannot properly pass on sounds to the brains. Passing on information from the ear takes place through neurotransmitters. Expectations are that the release of neurotransmitters has been decreased in the ear of the USH1B zebrafish.
Alaa Koleilat studied three already existing and by the FDA approved medicines that can increase the release of neurotransmitters. When administering these medicines to USH1B zebrafishes their swimming behaviour improved. This indicates a better functioning of the organ of balance. One medicine resulted in an improved reaction to sound stimulation. Although the results with USH1B zebrafishes are promising, these medicines cannot be administered to patients right away. As these medicines have been developed for other diseases, their effectiveness and safety in the ear is still unclear. Presently, studies are conducted to see whether these medicines also have a positive effect on the hearing and the organ of balance in a mouse model for USH1B.