A genetic mutation in two families with hereditary high frequency hearing loss was identified by Karen Avraham and colleagues at Tel Aviv University. The report can be found in this issue of the Journal of Clinical Investigation. The mutated gene encodes NESP4, a protein that is expressed in the outer nuclear membrane (ONM) of the hair cells of the ear. The gene has not previously been linked to hearing loss. Avraham and colleagues found that mutated NESP4 was mislocalized, disrupting a cellular complex known as the "linker of nucleoskeleton and cytoskeleton" or LINC, which maintains the position of the nucleus within the cell.
Hair cells in mice lacking NESP4 or another component of the LINC complex, SUN1, developed normally, but the mice developed hearing loss as they matured. These results demonstrate that the LINC complex is essential for hearing and indicate that nuclear positioning is important for the maintenance of normal hearing. In a companion commentary, Howard Worman of Columbia University discusses the role of the LINC complex in physiology and disease.