Autosomal recessive nonsyndromic hearing loss

Nearly all genes for autosomal recessive nonsyndromal inherited hearing los s (ARNSHL) localized thus far cause prelingual severe to profound or profou nd hearing impairment. Of the 25 reported loci, most have been identified u sing single consanguineous families. Six of these genes have been cloned an d encode a variety of proteins, including ion channels, extracellular matri x components, cytoskeletal components, and proteins essential for synaptic vesicular trafficking. One of these genes appears to be responsible for app roximately 50% of all congenital severe to profound or profound hearing los s in many world populations, and mutations in two other genes can lead to e ither syndromic or nonsyndromic forms of deafness. The identification of ad ditional genes that cause ARNSHL and elucidation of their function will ref ine our understanding of auditory physiology at the molecular level. (C) 20 00 Wiley-Liss, Inc.