scholarly journals Gjb3 Gene Mutations in Non-Syndromic Hearing Loss of Bloch, Kurd, and Turkmen Ethnicities in Iran

2020 ◽  
Author(s):  
Farnoush ALIAZAMI ◽  
Dariush D. FARHUD ◽  
Marjan ZARIF-YEGANEH ◽  
Siamak SALEHI ◽  
Azam HOSSEINIPOUR ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Dna Sequencing ◽  
Gene Mutations ◽  
Sensorineural Deafness ◽  
Heterozygous Mutation ◽  
Coding Region ◽  
Dominant Form ◽  
Direct Dna Sequencing ◽  
Junction Protein ◽  
Syndromic Hearing Loss

Background: Hearing loss (HL) is one of the most common heterogeneous congenital disabilities worldwide. Gap junction protein β-3 (GJB3) gene encodes Connexin31 protein (Cx31). The hereditary type of hearing impairment in this gene are known to cause both autosomal recessive and autosomal dominant form. In addition, GJB3 mutations have been involved in sensorineural deafness, erythrokeratodermia variabilis (EKV), and neuropathy diseases. We aimed to investigate GJB3 mutations in people suffering from HL among three different ethnicities of Iranian population (Baloch, Kurd, and Turkmen). Methods: In this descriptive study, 50 GJB2-negative non-syndromic hearing loss (NSHL) Iranian individuals from 3 ethnic groups of Baloch (n=17), Kurd (n =15) and Turkmen (n=18) were enrolled.  DNA extractions, PCR, and mutation detection was carried out for the two large deletions of the GJB6, del (GJB6 -D13S1830,) and del (GJB6 -D13S1854) followed by direct DNA sequencing method for the GJB3. Results: DNA sequencing of GJB3 was shown a missense heterozygous mutation rs199689484 (NM_024009.3) GJB3: c.340G>A (p.Ala114Thr) in a Baloch patient, and a polymorphism rs35983826 (NM_024009.3) GJB3: c.798C>T (p.Asn266=) in a Turkman patient, in coding region of the GJB3. We did not detect del (GJB6 -D13S1830) and del (GJB6 -D13S1854) among these three ethnicities in Iran. Conclusion: Deafness is a heterogeneous disorder. Specific genes and mutations contribute to hearing loss that varies from locus to locus as well as from population to population.

scholarly journals Mutation in second exon of MYO15A gene cause of nonsyndromic hearing loss and its association in the Arab population in Iran

Genetika ◽  
2016 ◽  
Vol 48 (2) ◽  
pp. 587-596 ◽  
Author(s):  
Samira Asgharzade ◽  
Morteza Chaleshtori ◽  
Mohammad Tabatabaifar ◽  
Somayeh Reisi ◽  
Mohammad Modaressi
Keyword(s):  
Hearing Loss ◽  
Gene Mutations ◽  
Amino Acid Position ◽  
Gjb2 Gene ◽  
Coding Region ◽  
Arab Population ◽  
Exon 2 ◽  
Direct Dna Sequencing ◽  
Syndromic Hearing Loss ◽  
Southwest Of Iran

Hearing loss is a genetically and clinically heterogeneous defect and more than 140 loci and 65 genes have been identified to cause autosomal recessive non-syndromic hearing loss (ARNSHL). According to the previous studies, mutations in GJB2 are estimated to be involved in 18.17% of ARNSHL cases in the Iranian population; as a result, the remaining 81.83% of this disorder is yet ambiguous. This study aimed to determine the contribution of DFNB3 in hearing loss as well as the frequency of gene mutations in a population (Arab tribal origin) in the Southwest of Iran. In this descriptive laboratory study, we included 25 families from the Southwest of Iran and negative GJB2 gene. Linkage analysis was performed by DFNB3 (MYO15A) molecular markers (STR). The families with hearing loss linked to this locus were further analyzed for mutation detection. MYO15A gene exons were amplified and analyzed using direct DNA sequencing. In studied families, one family displayed linkage to DFNB3 locus. Identified mutations include substitution and substitute C for A in 1047 location of coding region of MYO15A gene (c.1047 C>A) in exon 2 which cause to change Tyrosin to stop codons (P.Y349X), results in the premature truncation at amino acid position 349.

Screening for gap junction protein beta-2 gene mutations in Malays with autosomal recessive, non-syndromic hearing loss, using denaturing high performance liquid chromatography

2008 ◽  
Vol 122 (12) ◽  
pp. 1284-1288 ◽  
Author(s):  
Z Siti Aishah ◽  
M D Mohd Khairi ◽  
A R Normastura ◽  
Z Zafarina ◽  
B A Zilfalil
Keyword(s):  
Hearing Loss ◽  
High Performance Liquid Chromatography ◽  
Gap Junction ◽  
High Performance ◽  
Autosomal Recessive ◽  
Gene Mutations ◽  
Junction Protein ◽  
Syndromic Hearing Loss ◽  
Gap Junction Protein ◽  
Beta 2

AbstractObjective:To determine the frequency and type of gap junction protein beta-2 gene mutations in Malay patients with autosomal recessive, non-syndromic hearing loss.Methods:A total of 33 Malay patients with autosomal recessive, non-syndromic hearing loss were screened for mutations in the Cx26 coding region. Deoxyribonucleic acid was extracted from buccal swab samples and subjected to polymerase chain reaction. Slow-reannealing was performed, followed by screening using denaturing high performance liquid chromatography.Results:Eight of the samples (24.2 per cent) showed heterozygous peaks, and further sequencing of these samples revealed four patients (50.0 per cent) with the W24X mutation, two (25.0 per cent) with the V37I mutation and another two (25.0 per cent) with the G4D mutation.Conclusions:Analysis of buccal swab samples by denaturing high performance liquid chromatography is noninvasive and suitable for rapid and reliable screening of gap junction protein beta-2 gene mutations in patients with autosomal recessive, non-syndromic hearing loss. Malay patients with autosomal recessive, non-syndromic hearing loss have different kinds of gap junction protein beta-2 gene mutations which are rarely found in other populations.

scholarly journals SPECTRUM OF BETA GLOBIN GENE MUTATIONS IN EGYPTIAN CHILDREN WITH β- THALASSEMIA

2014 ◽  
Vol 6 (1) ◽  
pp. e2014071 ◽  
Author(s):  
MR El-Shanshory ◽  
Adel Abd Elhaleim Hagag
Keyword(s):  
Dna Sequencing ◽  
Blood Count ◽  
Complete Blood Count ◽  
Globin Gene ◽  
Gene Mutations ◽  
Thalassemia Major ◽  
Direct Dna Sequencing ◽  
Rare Mutations ◽  
Egyptian Children

Background: The molecular defects resulting in β-thalassemia phenotype, in the Egyptian population show a clear heterogenic mutations pattern. PCR based techniques, including direct DNA sequencing are effective on the molecular detection and characterization of these mutations. The molecular characterization of β-thalassemia is absolutely necessary for carrier screening, for genetic counseling, and to offer prenatal diagnosis.The aim of the work: was to evaluate the different β-globin gene mutations in one hundred Egyptian children with β-thalassemia. Patients and Methods: One hundred of β-thalassemic Egyptian children, covering most Egyptian Governorates. All patients were subjected to meticulous history taking, clinical examinations, complete blood count, complete blood count, hemoglobin electrophoresis, serum ferritin and direct fluorescent DNA sequencing of β-globin gene to detect the frequency of different mutations in studied patients. Results: The most common mutations among patients were IVS I-110(G>A) 48%, IVS I-6(T>C) 40%, IVS I-1(G>A)19%,IVS I-5(G>C)10%, IVS II-848 (C>A) 9%, IVS II-745(C>G) 8%, IVS II-1(G>A) 7%, codon"Cd"39(C> T) 4%,-87(C>G) 3% and the rare mutations were: Cd37 (G>A), Cd8 (-AA), Cd29(-G), Cd5 (-CT), Cd6(-A), Cd8/9(+G), Cd 106/107(+G), Cd27(C>T), IVS II-16(G> C), Cd 28 (-C), Cap+1(A>C), -88(C>A), all of these rare mutations were present in 1%. There was considerable variation in phenotypic severity among patients resulting from interaction of different β° and β+mutations, 79(79%) patients were thalassemia major (TM) and 21(21%) were thassemia intermedia (TI), without genotype phenotype association. Conclusion: Direct DNA sequencing provides insights for the frequency of different mutations in β- thalassemic patients including rare and /or unknown ones.

scholarly journals Prevalence of congenital non syndromic hearing loss among offspring of consanguineous marriage: a pilot study

2020 ◽  
Vol 6 (5) ◽  
pp. 874
Author(s):  
Gangadhar K. S. ◽  
Geetha Bhaktha ◽  
Manjula B. ◽  
Nageshwari P.
Keyword(s):  
Hearing Loss ◽  
Consanguineous Marriage ◽  
Gene Encoding ◽  
Single Nucleotide ◽  
Junction Protein ◽  
Study Population ◽  
Syndromic Hearing Loss ◽  
Gap Junction Protein ◽  
Polymerase Chain ◽  
Recessive Defect

<p class="abstract"><strong>Background:</strong> 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.</p><p class="abstract"><strong>Methods:</strong> 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.</p><p class="abstract"><strong>Results:</strong> 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.</p><p class="abstract"><strong>Conclusions:</strong> 25% of the study population had a mutation in their gene and the rest though had consanguineous marriage had not been affected genotypically.</p>

scholarly journals Genetics of non Syndromic Hearing Loss in the Republic of Macedonia

2012 ◽  
Vol 15 (Supplement) ◽  
pp. 57-59 ◽  
Author(s):  
Emilija Sukarova Stefanovska ◽  
D Plaseska Karanfilska ◽  
M Cakar ◽  
I Filipce
Keyword(s):  
Hearing Loss ◽  
Direct Sequencing ◽  
Gene Mutations ◽  
Developed Countries ◽  
Deaf Children ◽  
Mtdna Mutations ◽  
Republic Of Macedonia ◽  
Syndromic Hearing Loss ◽  
The Republic ◽  
Genetic And Environmental Factors

ABSTRACT Hearing impairment is the most common sensory deficit in humans affecting 1 in 1000 newborns. When present in an infant, deafness may have dramatic effects on language acquisition, seriously compromising the quality of their life. Deafness is influenced by both genetic and environmental factors, with inherited causes as the most prominent etiological factor in deafness in developed countries. The genetic basis of hearing loss is complex with numerous loci and genes underlying hereditary sensoryneural non syndromic hearing loss (NSHL) in humans. Despite the wide functional heterogeneity of the genes, mutations in the GJB2 gene are found to be the most common cause of sporadic and recessive NSHL in many populations worldwide. Molecular characterization of deafness in the Republic of Macedonia was performed in 130 NSHL profoundly deaf children from different ethnic origins. Molecular studies included direct sequencing of the GJB2 gene and specific polymerase chain reaction (PCR) analyses for the del(GJB6- D13S1830) mutation. Five common mitochondrial DNA (mtDNA) mutations [A1555G, 961delT+ C(n), T1095C, C1494T and A827G] were also analyzed using the SNaPShot method. In preliminary studies, GJB2 gene mutations were found in 36.4% of analyzed patients, with predominance of 35delG in Macedonian and Albanian patients and W24X in Gypsy patients, respectively. No del(GJB6- D13S1830) mutation was found. None of the analyzed deafness-associated mutations in mtDNA were identified in the studied patients

scholarly journals Butyrylcholinesterase (BCHE) Genotyping for Post-Succinylcholine Apnea in an Australian Population

2003 ◽  
Vol 49 (8) ◽  
pp. 1297-1308 ◽  
Author(s):  
Tina Yen ◽  
Brian N Nightingale ◽  
Jennifer C Burns ◽  
David R Sullivan ◽  
Peter M Stewart
Keyword(s):  
Dna Sequencing ◽  
Gene Mutations ◽  
University Teaching ◽  
Sequencing Analysis ◽  
Direct Dna Sequencing ◽  
Bche Activity ◽  
Mutation Screen ◽  
Sequencing Studies ◽  
Dna Sequencing Analysis ◽  
K Variant

Abstract Background: Measurement of plasma butyrylcholinesterase (BChE) activity and inhibitor-based phenotyping are standard methods for identifying patients who experience post-succinylcholine (SC) apnea attributable to inherited variants of the BChE enzyme. Our aim was to develop PCR-based assays for BCHE mutation detection and implement them for routine diagnostic use at a university teaching hospital. Methods: Between 1999 and 2002, we genotyped 65 patients referred after prolonged post-SC apnea. Five BCHE gene mutations were analyzed. Competitive oligo-priming (COP)-PCR was used for flu-1, flu-2, and K-variant and direct DNA sequencing analysis for dibucaine and sil-1 mutations. Additional DNA sequencing of BCHE coding regions was provided when the five-mutation screen was negative or mutation findings were inconsistent with enzyme activity. Results: Genotyping identified 52 patients with primary hypocholinesterasemia attributable to BCHE mutations, and in 44 individuals the abnormalities were detected by the five-mutation screen (detection rate, 85%). Additional sequencing studies revealed mutations in eight other patients, including five with novel mutations. The most common genotype abnormality was compound homozygous dibucaine and homozygous K-variant mutations. No simple homozygotes were found. Of the remaining 13 patients, 3 had normal BChE activity and gene, and 10 were diagnosed with hypocholinesterasemia unrelated to BCHE gene abnormalities. Conclusion: A five-mutation screen for investigation of post-SC apnea identified BCHE gene abnormalities for 80% of a referral population. Six new BCHE mutations were identified by sequencing studies of 16 additional patients.

scholarly journals Connexin 26 Gene Mutations in Non-Syndromic Hearing Loss Among Kuwaiti Patients

2014 ◽  
Vol 23 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Khalid Al-Sebeih ◽  
Marium Al-Kandari ◽  
Sadika A. Al-Awadi ◽  
Fatma F. Hegazy ◽  
Ghada A. Al-Khamees ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Gene Mutations ◽  
Connexin 26 ◽  
Syndromic Hearing Loss

Novel Mutations in LRTOMT Associated With Moderate Progressive Hearing Loss in Autosomal Recessive Inheritance

2015 ◽  
Vol 124 (1_suppl) ◽  
pp. 142S-147S ◽  
Author(s):  
Aya Ichinose ◽  
Hideaki Moteki ◽  
Mitsuru Hattori ◽  
Shin-ya Nishio ◽  
Shin-ichi Usami
Keyword(s):  
Hearing Loss ◽  
Massively Parallel Sequencing ◽  
Autosomal Recessive Inheritance ◽  
Japanese Patients ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Coding Region ◽  
Novel Mutations ◽  
First Case

Objective: We present a patient who was identified with novel mutations in the LRTOMT gene and describe the clinical features of the phenotype including serial audiological findings. Methods: One hundred six Japanese patients with mild to moderate sensorineural hearing loss from unrelated and nonconsanguineous families were enrolled in the study. Targeted genomic enrichment and massively parallel sequencing of all known nonsyndromic hearing loss genes were performed to identify the genetic cause of hearing loss. Results: Compound heterozygotes with a novel frame-shift mutation and a missense mutation were identified in the LRTOMT gene. The mutated residues were segregated in both alleles of LRTOMT, present within the LRTOMT2 protein coding region. The patient had moderate sloping hearing loss at high frequencies, which progressed at 1000 Hz and higher frequencies over a period of 6 years. Conclusion: Hearing loss caused by mutations in the LRTOMT gene is extremely rare. This is the first case report of a compound heterozygous mutation in a nonconsanguineous family.

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