Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.
- 7510T>C mutation
- genotype-phenotype correlation
- mitochondrial tRNASer(UCN) gene
- non-syndromic hearing impairment
Inherited hearing impairment is a highly heterogeneous group of disorders.1,2 In a majority of cases (about 70%), the hearing loss is non-syndromic, that is, it is not associated with any other clinical feature. It can be transmitted following autosomal (recessive or dominant), X linked, or maternal inheritance patterns. In the nuclear genome, more than 70 loci have been reported to be involved in non-syndromic hearing impairment, and 27 genes have been isolated from their critical intervals.2 In addition, a number of different mutations in several genes of the mitochondrial genome are responsible for hearing impairment.3,4 Some of these mutations result in a variety of additional clinical features in diverse organs. Mitochondrial syndromic hearing loss includes Kearns-Sayre syndrome (MIM 530000), MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes; MIM 540000), MERRF (myoclonus epilepsy and ragged red fibres; MIM 545000), and MIDD (maternally inherited diabetes mellitus and deafness; MIM 520000).3–5 In other cases, intrafamilial and interfamilial phenotypic variation is observed, a mutation causing syndromic or non-syndromic hearing impairment in different patients. This is the case for the 7445A>G mutation, causing hearing loss and palmoplantar keratoderma,6–10 and for 7472insC, responsible for hearing loss and neurological disorders (myoclonus epilepsy, ataxia, and cognitive impairment).11–14 Finally, other mutations have been associated so far only with hearing loss. These include mutations 7510T>C15 and 7511T>C16 in the tRNASer(UCN) gene, and 1095T>C17 and 1555A>G18 in the gene for the 12S rRNA. This last mutation is responsible for a dual phenotype, since it also confers increased susceptibility to the ototoxic action of aminoglycoside antibiotics.18
Most of the mutations causing maternally inherited non-syndromic …