GJB2-RELATED NON-SYNDROMIC HEARING LOSS VARIANTS’ SPECTRUM AND THEIR FREQUENCY IN TURKISH POPULATION

Objective: Hearing loss (HL) is one of the most prevalent chronic conditions in children and has consequences in speech, language, education, and social functioning which impede the quality of life. Due to the major involvement of the genetic factors in HL, especially non-syndromic HL (NSHL), geneti...

Full description

Saved in:
Bibliographic Details
Main Authors: Çağrı Güleç, Ayça Dilruba Aslanger, Volkan Karaman, Bernd Wollnik, Fatih Tepgeç, Hülya Kayserili Karabey, Zehra Oya Uyguner
Format: Article
Language:English
Published: Istanbul University Press 2022-03-01
Series:İstanbul Tıp Fakültesi Dergisi
Subjects:
Online Access:https://cdn.istanbul.edu.tr/file/JTA6CLJ8T5/75CDC79D85D949E3AF3FFBA43E15B97D
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850190343090208768
author Çağrı Güleç
Ayça Dilruba Aslanger
Volkan Karaman
Bernd Wollnik
Fatih Tepgeç
Hülya Kayserili Karabey
Zehra Oya Uyguner
author_facet Çağrı Güleç
Ayça Dilruba Aslanger
Volkan Karaman
Bernd Wollnik
Fatih Tepgeç
Hülya Kayserili Karabey
Zehra Oya Uyguner
author_sort Çağrı Güleç
collection DOAJ
description Objective: Hearing loss (HL) is one of the most prevalent chronic conditions in children and has consequences in speech, language, education, and social functioning which impede the quality of life. Due to the major involvement of the genetic factors in HL, especially non-syndromic HL (NSHL), genetic diagnosis and genetic counseling have a major impact on early management of the affected individuals and their families. Herein, we report the GJB2 gene variants and their frequencies in NSHL cohort at a tertiary health center between 2002-2021 to contribute for the future genetic counseling of Turkish NSHL patients. Materials and Methods: Two exons of the GJB2 gene were amplified in 402 NSHL patients by two separate PCR reactions and sequenced using the Sanger technique. Results: We found 13 different GJB2 variants in 35% (141/402) of the patients with NSHL. 53.9% were homozygous and 33.3% were compound heterozygous for the most common (59.21%) variant, c.35delG. Approximately 13% of the patients were found to carry the variants in the heterozygous state. The most frequent GJB2 variant c.35delG was followed by c.71G>A (6.38%), c.-23+1G>A (3.54%) and c.233delG (2.48%). We found heterozygous p.Asp50Glu (c.150C>A) alteration in four of eight patients with keratitis, ichthyosis, deafness (KID) and palmoplantar keratoderma (PPK) syndrome. Conclusion: Our results further emphasize the well-known prevalance of the GJB2 c.35delG alteration being the most predominant variant in the Turkish NSHL patients. The high rate of mono-allelic state could be considered as coincidental due to high allelic heterogeneity of NSHL, or possibly suggestive for digenic inheritance.
format Article
id doaj-art-bfb7f44ce4664e21a196e30ec0aa706d
institution OA Journals
issn 1305-6441
language English
publishDate 2022-03-01
publisher Istanbul University Press
record_format Article
series İstanbul Tıp Fakültesi Dergisi
spelling doaj-art-bfb7f44ce4664e21a196e30ec0aa706d2025-08-20T02:15:19ZengIstanbul University Pressİstanbul Tıp Fakültesi Dergisi1305-64412022-03-0185216216910.26650/IUITFD.1011501123456GJB2-RELATED NON-SYNDROMIC HEARING LOSS VARIANTS’ SPECTRUM AND THEIR FREQUENCY IN TURKISH POPULATIONÇağrı Güleç0https://orcid.org/0000-0002-1256-9574Ayça Dilruba Aslanger1https://orcid.org/0000-0003-1770-1762Volkan Karaman2https://orcid.org/0000-0001-8777-3548Bernd Wollnik3Fatih Tepgeç4https://orcid.org/0000-0001-8413-6949Hülya Kayserili Karabey5https://orcid.org/0000-0003-0376-499XZehra Oya Uyguner6https://orcid.org/0000-0002-2035-4338İstanbul Üniversitesi, İstanbul, Türkiyeİstanbul Üniversitesi, İstanbul, Türkiyeİstanbul Üniversitesi, İstanbul, Türkiyeİstanbul Üniversitesi, İstanbul, Türkiyeİstanbul Üniversitesi, İstanbul, Türkiyeİstanbul Üniversitesi, İstanbul, Türkiyeİstanbul Üniversitesi, İstanbul, TürkiyeObjective: Hearing loss (HL) is one of the most prevalent chronic conditions in children and has consequences in speech, language, education, and social functioning which impede the quality of life. Due to the major involvement of the genetic factors in HL, especially non-syndromic HL (NSHL), genetic diagnosis and genetic counseling have a major impact on early management of the affected individuals and their families. Herein, we report the GJB2 gene variants and their frequencies in NSHL cohort at a tertiary health center between 2002-2021 to contribute for the future genetic counseling of Turkish NSHL patients. Materials and Methods: Two exons of the GJB2 gene were amplified in 402 NSHL patients by two separate PCR reactions and sequenced using the Sanger technique. Results: We found 13 different GJB2 variants in 35% (141/402) of the patients with NSHL. 53.9% were homozygous and 33.3% were compound heterozygous for the most common (59.21%) variant, c.35delG. Approximately 13% of the patients were found to carry the variants in the heterozygous state. The most frequent GJB2 variant c.35delG was followed by c.71G>A (6.38%), c.-23+1G>A (3.54%) and c.233delG (2.48%). We found heterozygous p.Asp50Glu (c.150C>A) alteration in four of eight patients with keratitis, ichthyosis, deafness (KID) and palmoplantar keratoderma (PPK) syndrome. Conclusion: Our results further emphasize the well-known prevalance of the GJB2 c.35delG alteration being the most predominant variant in the Turkish NSHL patients. The high rate of mono-allelic state could be considered as coincidental due to high allelic heterogeneity of NSHL, or possibly suggestive for digenic inheritance.https://cdn.istanbul.edu.tr/file/JTA6CLJ8T5/75CDC79D85D949E3AF3FFBA43E15B97Dsensorineural hearing lossgjb2 genec.35delg alterationmutation frequency
spellingShingle Çağrı Güleç
Ayça Dilruba Aslanger
Volkan Karaman
Bernd Wollnik
Fatih Tepgeç
Hülya Kayserili Karabey
Zehra Oya Uyguner
GJB2-RELATED NON-SYNDROMIC HEARING LOSS VARIANTS’ SPECTRUM AND THEIR FREQUENCY IN TURKISH POPULATION
İstanbul Tıp Fakültesi Dergisi
sensorineural hearing loss
gjb2 gene
c.35delg alteration
mutation frequency
title GJB2-RELATED NON-SYNDROMIC HEARING LOSS VARIANTS’ SPECTRUM AND THEIR FREQUENCY IN TURKISH POPULATION
title_full GJB2-RELATED NON-SYNDROMIC HEARING LOSS VARIANTS’ SPECTRUM AND THEIR FREQUENCY IN TURKISH POPULATION
title_fullStr GJB2-RELATED NON-SYNDROMIC HEARING LOSS VARIANTS’ SPECTRUM AND THEIR FREQUENCY IN TURKISH POPULATION
title_full_unstemmed GJB2-RELATED NON-SYNDROMIC HEARING LOSS VARIANTS’ SPECTRUM AND THEIR FREQUENCY IN TURKISH POPULATION
title_short GJB2-RELATED NON-SYNDROMIC HEARING LOSS VARIANTS’ SPECTRUM AND THEIR FREQUENCY IN TURKISH POPULATION
title_sort gjb2 related non syndromic hearing loss variants spectrum and their frequency in turkish population
topic sensorineural hearing loss
gjb2 gene
c.35delg alteration
mutation frequency
url https://cdn.istanbul.edu.tr/file/JTA6CLJ8T5/75CDC79D85D949E3AF3FFBA43E15B97D
work_keys_str_mv AT cagrıgulec gjb2relatednonsyndromichearinglossvariantsspectrumandtheirfrequencyinturkishpopulation
AT aycadilrubaaslanger gjb2relatednonsyndromichearinglossvariantsspectrumandtheirfrequencyinturkishpopulation
AT volkankaraman gjb2relatednonsyndromichearinglossvariantsspectrumandtheirfrequencyinturkishpopulation
AT berndwollnik gjb2relatednonsyndromichearinglossvariantsspectrumandtheirfrequencyinturkishpopulation
AT fatihtepgec gjb2relatednonsyndromichearinglossvariantsspectrumandtheirfrequencyinturkishpopulation
AT hulyakayserilikarabey gjb2relatednonsyndromichearinglossvariantsspectrumandtheirfrequencyinturkishpopulation
AT zehraoyauyguner gjb2relatednonsyndromichearinglossvariantsspectrumandtheirfrequencyinturkishpopulation