Prevalence of congenital non syndromic hearing loss among offspring of consanguineous marriage: a pilot study
DOI:
https://doi.org/10.18203/issn.2454-5929.ijohns20201677Keywords:
Hearing impairment, GJB2 mutation, W24X gene, RFLPAbstract
Background: Mutations in the gene encoding the gap-junction protein connexin-26, is understood to be the most important cause of non-syndromic hearing loss (NSHL). An attempt to identify the single nucleotide polymorphism (SNP) for W24X mutation was done. Consanguineous marriage was seen among the NSHL subjects.
Methods: SNP was identified using restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR). Forty-five subjects were screened for congenital hearing loss. Twenty subjects matched the inclusion criteria and were included in the study.
Results: 5 out of 20 subjects were found to have mutation i.e., 25%. Though consanguinity is known to cause autosomal recessive defect, the same could not be depicted in this study.
Conclusions: 25% of the study population had a mutation in their gene and the rest though had consanguineous marriage had not been affected genotypically.
References
Fortnum H, Davis A. Epidemiology of permanent childhood hearing impairment in Trent Region, 1985-1993. Br J Audiol. 1997;316:409-16.
Morton NE. Genetic epidemiology of hearing impairment. Ann NY Acad Sci. 1991;630:16-31.
Kelsell DP, Dunlop J, Stevens HP, Lench NJ, Liang JN, Parry G, et al. Connexin 26 mutations in hereditary non-syndromic sensorineural deafness. Nature. 1997;387: 80-3.
Kikuchi T, Adams JC, Paul DL, Kimura RS. Gap junction systems in the rat vestibular labyrinth: immuno histo chemical and ultrastructural analysis. ActaOtolaryngol. 1994;114:520-8.
Van Camp G, Smith RJH. The Hereditary Hearing Loss Homepage. 2017. Available at: https://hereditaryhearingloss.org/. Accessed on 18 July 2019.
Maheswari M, Vijaya R, Ghosh M, Shastri S, Kabra M, Menon PSN. Screening of families with autosomal recessive non-syndromic hearing impairment (ARNSHI) for mutations in GJB2 gene: Indian scenario. Am J Med Genet. 2003;120:180-4.
Shankar RM, Girirajan S, Dagan O, Shankar RHM, 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;40:68.
Ramchander PV, Nandur VU, Dwarakanath K, Vishnupriya S, Padma T. Prevalence of Cx26 (GJB2) gene mutations causing recesive non syndromic hearing impairment in india. Int J Hum Genetic. 2005;5:241-6.
Sobe T, Erlich P, Berry A, Korostichevsky M, Vreugde S, Avraham KB, et al. High frequency of the deafness-associated 167delT mutation in the connexin 26 (GJB2) gene in Israeli Ashkenazim. Am J Med Genet. 1999;86:499-500.
Kelley PM, Harris DJ, Comer BC, Askew JW, Fowler T, Smith SD, et al. Novel mutations in the connexin 26 gene (GJB2) that cause autosomal recessive (DFNB1) hearing loss. Am J Hum Genet. 1998;62:792-9.
Abe S, Usami S, Shinkawa H, Kelley PM, Kimberling WJ. Prevalent connexin 26 gene (GJB2) mutations in Japanese. J Med Genet. 2000;37:41-3.
