Clue to a New Deafness Gene: A Large Chinese Nonsyndromic Hearing Loss Family Linked to DFNA4

Abstract

Hereditary hearing loss is one of the most common neurosensory defects in humans. Approximately 70% of cases are nonsyndromic and could be inherited in autosomal dominant, autosomal recessive, mitochondrial, X-linked, and Y-linked manners (Wang et al., 2004; Alford, 2011). The autosomal dominant type, comprising 15%–20% of nonsyndromic hearing loss, is monogenic and genetically heterogeneous. Since the first dominant deafness locus (DFNA1) was identified in 1992, a total of 64 DFNA loci have been mapped (DFNA1–DFNA64), and 27 corresponding genes have been identified (http://hereditaryhearingloss.org). Previous studies have revealed that one deafness locus can be linked to more than one gene (Bayazit and Yilmaz, 2006), and the question “one locus, how many genes?” was first raised about a decade ago (Van-Hauwe et al., 1999). So far, several loci, including DFNA2 and DFNA3, have been shown to be related to one or more genes, showing high genetic heterogeneity in hereditary hearing loss (Grifa et al., 1999; Goldstein and Lalwani, 2002; Yan et al., 2011).