Identification of both MT-RNR1 m.1555A>G and bi-allelic GJB2 mutations in probands with non-syndromic hearing loss

Yongchuan Chai; Lianhua Sun; Xiuhong Pang; Xiaowen Wang; Dongye Chen; Ying Chen; Hao Wu; Tao Yang

doi:10.1016/j.ijporl.2014.01.011

Identification of both MT-RNR1 m.1555A>G and bi-allelic GJB2 mutations in probands with non-syndromic hearing loss

Int J Pediatr Otorhinolaryngol. 2014 Apr;78(4):614-7. doi: 10.1016/j.ijporl.2014.01.011. Epub 2014 Jan 16.

Authors

Yongchuan Chai¹, Lianhua Sun¹, Xiuhong Pang¹, Xiaowen Wang¹, Dongye Chen¹, Ying Chen¹, Hao Wu², Tao Yang³

Affiliations

¹ Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China.
² Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China. Electronic address: wuhao622@sina.cn.
³ Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University School of Medicine, Shanghai, China. Electronic address: yangtfxl@sina.com.

PMID: 24507663
DOI: 10.1016/j.ijporl.2014.01.011

Abstract

Objectives: Mutations in GJB2 and MT-RNR1 are common causes for non-syndromic sensorineural hearing loss (NSHL). In this study, we investigated the co-existence of both MT-RNR1 and bi-allelic GJB2 mutations in a large number of simplex and multiplex probands with NSHL.

Methods: 485 simplex and 134 multiplex probands with NSHL were recruited for mutation screening of GJB2 and MT-RNR1 by bidirectional sequencing. Clinical features of probands with both MT-RNR1 and bi-allelic GJB2 mutations were further analyzed in comparison with extended family members.

Results: MT-RNR1m.1555A>G and bi-allelic GJB2 mutations were both detected in one (0.21%) simplex probands and two (1.49%) multiplex probands. Variable hearing phenotypes were found in a pair of siblings with both MT-RNR1 and bi-allelic GJB2 mutations.

Conclusion: MT-RNR1 and bi-allelic GJB2 mutations may co-exist not only in multiplex probands but also in simplex probands. The variable hearing phenotypes in closely-related family members may reflect the co-existence of different molecular causes and prompt extended genetic tests.

Keywords: Expression variability; GJB2; MT-RNR1; Mutation; Penetrance; Sensorineural hearing loss.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Alleles
Child
Child, Preschool
Cohort Studies
Connexin 26
Connexins / genetics*
DNA, Mitochondrial / genetics*
Female
Genetic Predisposition to Disease / epidemiology*
Genetic Testing
Hearing Loss, Sensorineural / genetics*
Heterozygote
Humans
Infant
Infant, Newborn
Male
Mutation*
Pedigree
RNA, Ribosomal / genetics*

Substances

Connexins
DNA, Mitochondrial
GJB2 protein, human
RNA, Ribosomal
Connexin 26

Supplementary concepts

Nonsyndromic sensorineural hearing loss