Israeli scientists help solve genetic mystery linking hearing loss and gray hair

An international team including researchers from Tel Aviv University, Bethlehem University, and the University of Washington identified a rare genetic variant in the FMN1 gene that causes congenital hearing loss and silvery-gray hair in a Palestinian family. The study, published in PNAS, used mouse models to show that loss of the Formin-1 protein disrupts inner ear structure and melanosome transport, linking the two conditions. The discovery adds FMN1 to over 200 genes essential for hearing and highlights a clinical clue for diagnosis.

An international team of researchers has solved a genetic mystery linking congenital hearing loss to silvery-gray hair in children. The study, published in the Proceedings of the National Academy of Sciences, focused on a Palestinian family in which four children from three sets of cousins were born with bilateral moderate hearing loss and silver-gray hair. Genomic analysis revealed that the affected children carried two copies of a rare variant in the FMN1 gene, leading to loss of the Formin-1 protein. Using mouse models created in the early 1990s whose hearing had not previously been studied, the team showed that loss of Formin-1 disrupts the microtubule architecture in the cochlea, the hearing organ of the inner ear. The protein is also involved in transporting melanosomes, the pigment-containing organelles that contribute to hair color, explaining the dual effect. The discovery adds FMN1 to the more than 200 genes known to be essential for hearing. Senior author Prof. Karen Avraham of Tel Aviv University noted that the pigmentation change could serve as a clinical clue for identifying FMN1-related hearing loss. The collaboration between Israeli, Palestinian, and American scientists has produced 24 co-authored publications over nearly 30 years.