Fatemeh Bitarafan1, Seyed Yousef Seyedena1, Mahdi Mahmoudi2, Masoud Garshasbi3. 1. Department of Biology, Faculty of Biological Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran. 2. Rheumatology Research Center, Tehran University of Medical Sciences, Tehran, Iran. 3. Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Teheran, Iran.
Abstract
BACKGROUND: The extremely high genetic heterogeneity of hearing loss due to diverse group of genes encoding proteins required for development, function, and maintenance of the complex auditory system makes the genetic diagnosis of this disease challenging. Up to now, 121 different genes have been identified for nonsyndromic hearing loss (NSHL), of which 76 genes are responsible for the most common forms of NSHL, autosomal recessive nonsyndromic hearing loss (ARNSHL). METHODS: After excluding mutations in the most common ARNSHL gene, GJB2, by Sanger sequencing, genetic screening for a panel of genes responsible for hereditary hearing impairment performed in 9 individuals with ARNSHL from unrelated Iranian consanguineous pedigrees. RESULTS: One compound heterozygote and eight homozygote variants, of which five are novel, were identified: CDH23:p.(Glu1970Lys), and p.(Ala1072Asp), GIPC3:p.(Asn82Ser), and (p.Thr41Lys), MYO7A:p.[Phe456Phe]; p.[Met708Val], and p.(Gly163Arg), TECTA:p.(Leu17Leufs*19), OTOF:c.1392+1G>A, and TRIOBP:p.(Arg1068*). Sanger sequencing confirmed the segregation of the variants with the disease in each family. CONCLUSION: Finding more variants and expanding the spectrum of hearing impairment mutations can increase the diagnostic value of molecular testing in the screening of patients and can improve counseling to minimize the risk of having affected children for at risk couples.
BACKGROUND: The extremely high genetic heterogeneity of hearing loss due to diverse group of genes encoding proteins required for development, function, and maintenance of the complex auditory system makes the genetic diagnosis of this disease challenging. Up to now, 121 different genes have been identified for nonsyndromic hearing loss (NSHL), of which 76 genes are responsible for the most common forms of NSHL, autosomal recessive nonsyndromic hearing loss (ARNSHL). METHODS: After excluding mutations in the most common ARNSHL gene, GJB2, by Sanger sequencing, genetic screening for a panel of genes responsible for hereditary hearing impairment performed in 9 individuals with ARNSHL from unrelated Iranian consanguineous pedigrees. RESULTS: One compound heterozygote and eight homozygote variants, of which five are novel, were identified: CDH23:p.(Glu1970Lys), and p.(Ala1072Asp), GIPC3:p.(Asn82Ser), and (p.Thr41Lys), MYO7A:p.[Phe456Phe]; p.[Met708Val], and p.(Gly163Arg), TECTA:p.(Leu17Leufs*19), OTOF:c.1392+1G>A, and TRIOBP:p.(Arg1068*). Sanger sequencing confirmed the segregation of the variants with the disease in each family. CONCLUSION: Finding more variants and expanding the spectrum of hearing impairment mutations can increase the diagnostic value of molecular testing in the screening of patients and can improve counseling to minimize the risk of having affected children for at risk couples.
Authors: Maryam Beheshtian; Mojgan Babanejad; Hela Azaiez; Niloofar Bazazzadegan; Diana Kolbe; Christina Sloan-Heggen; Sanaz Arzhangi; Kevin Booth; Marzieh Mohseni; Kathy Frees; Mohammad Hossein Azizi; Ahmad Daneshi; Mohammad Farhadi; Kimia Kahrizi; Richard Jh Smith; Hossein Najmabadi Journal: Arch Iran Med Date: 2016-10-01 Impact factor: 1.354
Authors: Nika V Petrova; Andrey V Marakhonov; Natalia V Balinova; Anna V Abrukova; Fedor A Konovalov; Sergey I Kutsev; Rena A Zinchenko Journal: Genes (Basel) Date: 2021-05-27 Impact factor: 4.096