Relationship between Mitochondrial DNA Point Mutation and Noise-induced Sensorineural Hearing Loss / 항공우주의학회지

BACKGROUND: A different sequence change in the mitochondrial 12S rRNA gene has been proposed as a candidate mutation in the sensorineural hearing loss. The purpose of this study was to study the association between the noise-induced sensorineural hearing loss and A to G mutation at nucleotide 1555 of mitochondrial DNA. METHODS: subjects were reviewed by history and medical records, and audiological and clinical data were obtained. Blood sampling was done on 101 normal controls, 51 with noise-induced sensorineural hearing loss, and 12 with sensorineurnal deafness. The DNA of these individuals were extracted, and mitochondrial genome were analyzed by polymerase chain reaction (PCR). Subsequently, the coding sequence of mitochondrial genome was sequenced and compared to the normal sequence, and all sequence variations were analyzed by restriction endonuclease BsmA I. RESULTS: Mitochondrial DNA mutant (1555A-->G) was not detected by PCR in all Korean patients with noise-induced hearing loss, sensorineural hearing loss, and in normal controls with no hearing loss. The DNA sequencing of PCR products did not reveal an A to G substitution at nucleotide 1,555 of mitochondrial DNA. CONCLUSION: This result suggests that the noise-induced sensorineural hearing loss is not associated with mitochondrial DNA mutation (1555A-->G).

Mitochondrial DNA A3243G mutation in noise-induced sensorineural hearing loss / 대한산업의학회지

OBJECTIVES: A different sequence change, in the mitochondrial tRNA gene, has been proposed as a candidate mutation in the sensorineurnal hearing loss. The purpose of current study is to identify the association between the noise-induced sensorineurnal hearing loss and the A to G mutation at nucleotide 3243 of mitochondrial DNA. METHODS: Subjects were established by history and chart review, and audiological and clinical data were obtained. Blood was sampled from 101 controls, 50 noise-induced hearing loss, and 12 sensorineural deafness. The DNA of these individuals was extracted, and mitochondrial genome was analyzed by polymerase chain reaction. Subsequently, the coding sequence of mitochondrial genome was sequenced, and compared to the normal sequence, and all sequence variations were analyzed by restriction endonuclease ApaI. RESULTS: Mitochondrial DNA mutation (3243A->G) was not detected by polymerase chain reaction (PCR) in any patients with noise-induced hearing loss, sensorineural hearing loss, and normal control without hearing loss in Koreans. The DNA sequencing of PCR products did not revealed an A to G substitution at nucleotide 3243 of mitochondrial DNA. CONCLUSIONS: The noise-induced sensorineural hearing loss was not associated with mitochondrial DNA mutation (3243A->G)