ABSTRACT
DFNA1 hearing loss is dominantly inherited, progressive, and nonsyndromic. It is caused by a truncating mutation in the human homolog of Drosophila diaphanous, a member of the formin family of proteins. In this chapter we review the clinical features associated with DFNA1, the causative diaphanous mutation, the homologs of diaphanous in humans and other species, and functional roles of diaphanous. Diaphanous is a target of Rho and a binding partner of profilin, which regulates actin polymerization. Diaphanous is required for organization of cytoskeletal structures, including actin stress fibers, focal adhesions, microtubules, and contractile rings, and hence for maintenance of normal cell size, shape, and division.
