Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-28T18:34:54.338Z Has data issue: false hasContentIssue false

High frequency of heterozygosity in GJB2 mutations among patients with non-syndromic hearing loss

Published online by Cambridge University Press:  23 June 2008

G Khandelwal
Affiliation:
Department of Otolaryngology and Head and Neck Surgery, Post-Graduate Institute of Medical Education and Research, Chandigarh, India
S Bhalla
Affiliation:
Department of Otolaryngology and Head and Neck Surgery, Post-Graduate Institute of Medical Education and Research, Chandigarh, India
M Khullar
Affiliation:
Department of Experimental Medicine and Biotechnology, Post-Graduate Institute of Medical Education and Research, Chandigarh, India
N K Panda*
Affiliation:
Department of Otolaryngology and Head and Neck Surgery, Post-Graduate Institute of Medical Education and Research, Chandigarh, India
*
Address for correspondence: Dr Naresh K Panda, Department of Otolaryngology and Head and Neck Surgery, Post-Graduate Institute of Medical Education and Research, Chandigarh, India160012. Fax: +91 172 2744401 E-mail: npanda59@yahoo.co.in

Abstract

Objective:

To determine the prevalence of GJB2 mutations among subjects with congenital, non-syndromic, sensorineural hearing loss, within a north Indian population.

Materials and methods:

This was a case–control study in which the frequencies of the three most prevalent GJB2 mutations (35delG, W24X and 167delT) were studied. Polymerase chain reaction restriction fragment length polymorphism assays were performed to detect these mutations. The entire coding region of the GJB2 gene was sequenced in all patients, and also in any of their family members who showed GJB2 mutations.

Results:

The 35delG mutation was found to be the most prevalent mutation (21 per cent), followed by the W24X mutation (7 per cent). This is the first report of the 35delG mutation in an Indian population. One patient was a compound heterozygote for 35delG/W24X. The 167delT mutation was not observed in any patient.

Conclusions:

These findings challenge the classical view that the W24X variant of the GJB2 gene represents a single ‘founder’ mutation.

Type
Main Articles
Copyright
Copyright © JLO (1984) Limited 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Unger, VM, Kumar, NM, Gilula, NB, Yeager, M. Three-dimensional structure of a recombinant gap junction membrane channel. Science 1999;283:1176–80CrossRefGoogle ScholarPubMed
2 Green, GE, Scott, DA, McDonald, JM, Woodworth, GG, Sheffield, VC, Smith, RJ. Carrier rates in the Midwestern United states for GJB2 mutations causing inherited deafness. JAMA 1999;281:2211–16Google Scholar
3 Morell, RJ, Kim, HJ, Hood, LJ, Goforth, L, Friderici, K, Fisher, R et al. Mutations in the connexin 26 gene (GJB2) among Ashkenazi Jews with non syndromic recessive deafness. N Engl J Med 1998;339:1500–5CrossRefGoogle Scholar
4 Sobe, T, Vreugde, S, Shahin, H, Berlin, M, Davis, N, Kanaam, M et al. The prevalence and expression of inherited connexin 26 mutations associated with nonsyndromic hearing loss in the Israeli population. Hum Genet 2000;106:50–7Google Scholar
5 Ramshankar, M, Girirajan, S, Dagan, O, Ravi Shankar, HM, Jalvi, R, Rangasayee, R et al. Contribution of connexin 26 (GJB2) mutations and founder effect to non-syndromic hearing loss in India. J Med Genet 2003;40:e68–72Google Scholar
6 Maheshwari, M, Vijaya, R, Ghosh, M, Shastri, S, Kabra, M, Menon, PS. Screening of families with autosomal recessive nonsyndromic hearing impairment (ARNSHI) for mutations in GJB2: Indian scenario. Am J Med Genet 2003;120A:180–4Google Scholar
7 Ramchander, PV, Nandur, VU, Dwarakanath, K, Vishnupriya, S, Padma, T. Prevalence of Cx26 (GJB2) gene mutations causing recessive nonsyndromic hearing impairment in India. Int J Hum Genet 2005;5(4):241–6Google Scholar
8 Gill, P, Werrett, DJ. Exclusion of a man charged with murder by DNA fingerprinting. Forensic Sci Int 1987;35:145–8Google Scholar
9 Khullar, M, Bhalla, S, Sharma, R, Sehrawat, BS, Panda, NK. PCR-RFLP assay for W24X mutation detection in non-syndromic hearing loss subjects. J Med Genet 2003;40:68eGoogle Scholar
10 Bors, A, Andrikovics, H, Kalmar, L, Erdei, N, Galambos, S, Losonczi, A et al. Frequencies of two common mutations (c.35delG and c.167delT) of the connexin 26 gene in different populations of Hungary. Int J Mol Med 2004;14(6):1105–8Google Scholar
11 Mehmet, S, Al-Wardy, N, Al-Khabory, M. A polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) test to detect the common mutation (35delG) in the connexin-26 gene. SQU Journal for Scientific Research 2001;1:912Google Scholar
12 Rabionet, R, Gasparinin, P, Estivill, X. Molecular genetics of hearing impairment due to mutations in gap junction genes encoding beta connexins. Hum Mutat 2000;16:190202Google Scholar
13 Denoyelle, F, Marlin, S, Weil, D, Moatti, L, Chauvin, P, Garabedian, EN et al. Clinical features of the prevalent form of childhood deafness, DFNB1, due to a connexin26 gene defect: implications for genetic counselling. Lancet 1999;353:1298–303CrossRefGoogle ScholarPubMed
14 Murgia, A, Orzan, E, Polli, R, Martella, M, Vinanzi, C, Leonardi, E et al. CX26 deafness: mutation analysis and clinical variability. J Med Genet 1999;36:829–32Google ScholarPubMed
15 Riazuddin, S, Castelein, CM, Ahmed, ZM, Lalwani, AK, Mastroianni, MA, Naz, S et al. Dominant modifier DFNM1 suppresses recessive deafness DFNB26. Nature Genet 2000;26:431–4CrossRefGoogle ScholarPubMed
16 Samanich, J, Lowes, C, Burk, R, Shanske, S, Lu, J, Shanske, A et al. Mutations in GJB2, GJB6, and mitochondrial DNA are rare in African American and Caribbean Hispanic individuals with hearing impairment. Am J Med Genet 2007;143A(8):830–8CrossRefGoogle ScholarPubMed