These proteins consist of 4 hydrophobic transmembrane domains, 2 extracellular loops and short cytoplasmic tails at N and C-termini containing YV and PDZ-domain binding motifs. Claudin 14, a 25kD glycoprotein, is a novel member of this family. It is a vital component of inner ear tight junction strands. Its expression has been observed in sensory epithelium of inner organ of Corti, vestibular system, kidney and Liver. Mutations in Claudin 14 cause a congenital autosomal recessive form of nonsyndromic sensorineural deafness in humans.