A gene of chromosome 6q23 encodes the 640 amino acid protein, EYA4 (eyes absent) (1). EYA is one of four members of the eyes absent family (1). A 271 amino acid domain at the carboxyl terminal is highly conserved amongst the members of the eyes absent family (1). EYA4 is expressed in the craniofacial mesenchyme, the dermamyotome, and the limb (1). The conserved region in other EYA proteins interacts with SIX, DACH, and G-proteins, which regulate transcription in early embryonic development (1,2,3,4). SIX translocates EYA1-3 to the nucleus, and G-proteins can stop this interaction (3,4). Premature stop codon mutations in EYA4 cause postlingual, progressive autosomal dominant hearing loss in humans (2). This shows that EYA4 is also vital to the mature organ of Corti (2). EYA4 may cause oculo-dento-digital syndrome, based on its expression pattern and map postion (1).
