<abstract xmlns="http://www.w3.org/1999/xhtml">Variations in mitochondrial genome have been found to be associated with hearing loss. Of these, the mitochondrial 12S rRNA and tRNASer(UCN) are the hot-spots for pathogenic variants associated with deafness. To understand the putative role of mitochondrial DNA (mtDNA) variants in hearing loss, we recently screened the variants in mitochondrial genomes in patients with deafness from the Hangzhou area of Zhejiang Province, People’s Republic of China (PRC). In this study, we describe a maternally-inherited Han Chinese family with high penetrance of hearing loss, notably, the penetrance of hearing loss in this family were 80.0 and 40.0%, when the aminoglycoside was included or excluded. Three matrilineal relatives in this pedigree exhibited different levels of hearing loss with different age at onset. In addition, sequence analysis of the complete mitochondrial genome showed the presence of the well-known C1494T pathogenic variant in the <italic>12S rRNA</italic> gene and the G7444A pathogenic variant in the COI/ tRNASer(UCN). The C1494T anomaly had been reported to be a pathogenic mutation associated with aminoglycoside-induced and nonsyndromic hearing loss (AINHL), while the G7444A was considered as a secondary mutation associated with deafness. However, the lack of functional variants in <italic>GJB2</italic> and <italic>TRMU</italic> genes suggested that nuclear modified genes may not play important roles in deafness expression. Thus, the combination of G7444A and C1494T pathogenic variants in the mitochondrial genome may account for the high penetrance of hearing loss in this Chinese family.</abstract>

Variations in mitochondrial genome have been found to be associated with hearing loss. Of these, the mitochondrial 12S rRNA and tRNASer(UCN) are the hot-spots for pathogenic variants associated with deafness. To understand the putative role of mitochondrial DNA (mtDNA) variants in hearing loss, we recently screened the variants in mitochondrial genomes in patients with deafness from the Hangzhou area of Zhejiang Province, People’s Republic of China (PRC). In this study, we describe a maternally-inherited Han Chinese family with high penetrance of hearing loss, notably, the penetrance of hearing loss in this family were 80.0 and 40.0%, when the aminoglycoside was included or excluded. Three matrilineal relatives in this pedigree exhibited different levels of hearing loss with different age at onset. In addition, sequence analysis of the complete mitochondrial genome showed the presence of the well-known C1494T pathogenic variant in the 12S rRNA gene and the G7444A pathogenic variant in the COI/ tRNASer(UCN). The C1494T anomaly had been reported to be a pathogenic mutation associated with aminoglycoside-induced and nonsyndromic hearing loss (AINHL), while the G7444A was considered as a secondary mutation associated with deafness. However, the lack of functional variants in GJB2 and TRMU genes suggested that nuclear modified genes may not play important roles in deafness expression. Thus, the combination of G7444A and C1494T pathogenic variants in the mitochondrial genome may account for the high penetrance of hearing loss in this Chinese family.

The mitochondrial COI/tRNASER(UCN) G7444A mutation may be associated with hearing impairment in a Han Chinese family

Balkan Journal of Medical Genetics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The mitochondrial COI/tRNA G7444A mutation may be associated with hearing impairment in a Han Chinese family

Variations in mitochondrial genome have been found to be associated with hearing loss. Of these, the mitochondrial 12S rRNA and tRNASer(UCN) are the hot-spots...

The mitochondrial COI/tRNA^SER(UCN) G7444A mutation may be associated with hearing impairment in a Han Chinese family

Article Category: Original Article

Published Online: Dec 29, 2017

Page range: 43 - 49

DOI: https://doi.org/10.1515/bjmg-2017-0025

Keywords
C1494T, G7444A, Chinese family, Deafness, Mitochondrial DNA (mtDNA), Pathogenic variants

© 2017 Ding Y, Xia B-H, Teng Y-S, Zhuo G-C, Leng J-H, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The mitochondrial COI/tRNASER(UCN) G7444A mutation may be associated with hearing impairment in a Han Chinese family

Article Category: Original Article

Published Online: Dec 29, 2017

Page range: 43 - 49

DOI: https://doi.org/10.1515/bjmg-2017-0025

KeywordsC1494T, G7444A, Chinese family, Deafness, Mitochondrial DNA (mtDNA), Pathogenic variants

© 2017 Ding Y, Xia B-H, Teng Y-S, Zhuo G-C, Leng J-H, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The mitochondrial COI/tRNA^SER(UCN) G7444A mutation may be associated with hearing impairment in a Han Chinese family

Keywords
C1494T, G7444A, Chinese family, Deafness, Mitochondrial DNA (mtDNA), Pathogenic variants