Related Experiment Video
Updated: Jul 7, 2026
Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss
Published on: January 25, 2016
A maternal hereditary deafness pedigree of the A1555G mitochondrial mutation, causing aminoglycoside ototoxicity
1Department of Neurology, Shanghai Number Five Hospital, Fudan University, Shanghai, PR China.
Objective:
To characterise the hearing loss, and the frequency of the mitochondrial deoxyribonucleic acid 12S ribosomal ribonucleic acid A1555G mutation, in a large pedigree of aminoglycoside-induced deafness.
Design:
Hearing loss was clinically assessed. Blood samples were collected from 27 family members (19 matrilinear and eight non-matrilinear) and leukocyte deoxyribonucleic acid was extracted. Mitochondrial deoxyribonucleic acid fragments, spanning the 1555 location, were amplified by polymerase chain reaction. Polymerase chain reaction products were analysed by restriction fragment length polymorphism and deoxyribonucleic acid sequencing.
Results:
We detected the A1555G mutation in all 19 matrilinear relatives. Of these 19, two exhibited congenital deafness, four had no hearing deficits and the remaining 13 suffered mild to profound hearing loss.
Conclusion:
We confirmed that the A1555G mutation is a 'hot spot' associated with non-syndromic, inherited hearing loss. This mutation may play a vital role in the pathogenesis of hearing impairment, and can result in various grades of deafness.
Related Concept Videos
02:59Animal Mitochondrial Genetics
01:11Genetic Lingo
01:35Pedigree Analysis
01:33Pleiotropy
02:41Lethal Alleles
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
01:43Incomplete Dominance