Studies on molecular genetic aspects of nonsyndromic hereditary hearing loss

Abstract

The mechanism of hearing is a complex biological process. In humans, a number of genes are known to underlie this process. Understanding of these genes in auditory physiology is providing substantial information regarding biological aspects of the normal process of hearing and its impairment. In the last 10 years or so, advances in the area of human genetics and cell biology have provided major insights into the mechanisms involved in the development, function and dysfunction of the cochlea, the auditory signal transduction apparatus in humans. The progress in identifying genes involved in hearing impairment has been remarkable in the recent years. This is evident from the fact that in the last ten years or so, mutations in 46 different genes have been implicated in human NSHL (Friedman and Griffith 2003, Hilgert et al. 2008). Before human genome sequence became available, about 13 genes had been identified for human nonsyndromic hearing loss, whereas after the availability of human genome sequence in the year 2000, 33 additional genes have been identified. Information about these genes is revolutionizing our knowledge of the molecular processes involved in hearing and their alteration leading to hearing loss. Although there is a significant progress in understanding the genetic aspects of hereditary hearing loss, it is clear that more genes and mutations await discovery.