scholarly journals Connexin 26 (GJB2) Gene Mutations Linked With Autosomal Recessive Nonsyndromic Sensorineural Hearing Loss in Iraqi Population

Author(s):  
Anwar Madlool Al-janabi ◽  
Habeeb Shuhaib Ahmmed ◽  
Salih Mahdi Al-Khafaji

Abstract Background:Deafness is a total or partial hearing loss that may appear at any ages with different degrees of severity. Approximately 50% of hearing loss have a genetic origin, among them, the nonsyndromic sensorineural deafness represents about 70% of the cases. From them 80% corresponding to autosomal recessive inheritance deafness. Objective: Autosomal recessive deafness was not been studied enough at molecular level in Iraq, so this study aimed to detect the prevalence of the three most common mutations of Connexin 26 (GJB2) gene in nonsyndromic sensorineural deafness for Iraqi population.Method: The current case-control study was conducted from January 2018 to January 2020 at molecular laboratory in Anatomy and Histology Department/ faculty of Medicine/ Kufa University/Najaf/ Iraq. The study was included 95 deaf patients (55 males and 40 females) their age range between 11-40 years old and 21.5 ± 6.3 year (mean ± SD) and 110 healthy control group, their ages range between 10-40 years old and 20.1 ± 5.9 year (mean ± SD), these two groups were matched in age and gender. In order to detect c.35delG, 235delC and 167delT mutations in GJB2 gene, we were employed the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) technique.Results: From 95 deaf patients with ARNSHL who were participated in this study, the c.35delG was the main frequent mutation encountered with GJB2 gene, among them 35(36.8%) were homozygous, 40(42.1%) were heterozygous and 20 (21.1%) were wild genotypes. The second degree mutation in GJB2 gene was c.235delC mutation, which from the 95 deaf patients, there were 21 (22.1%) carried out homozygous, 33 (34.7%) heterozygous and 42(44.2%) wild genotypes. None of the 95 deaf patients were showed the c.167delT mutation, on the other hand these variants were not detected in healthy control group which was studied parallel with patients group.Conclusion: Our data conclude that the GJB2 c.35delG and c.235delC gene mutations were the main cause of ARNSHL in Iraqi deaf population.

2021 ◽  
Author(s):  
Anwar Madlool Al-janabi ◽  
Habeeb Shuhaib Ahmmed ◽  
Salih Mahdi Alkhafaji

Abstract Objective: This study aimed to detect the frequency of the three most common mutations of GJB2 in nonsyndromic sensorineural deafness for Iraqi population.Method: The current case-control study was conducted from January 2018 to November 2019 at ENT Departments from middle Euphrates region of Iraq. The study was included 95 deaf patients group (55 males and 40 females) their age range between 11-40 years old and 21.5 ± 6.3 year (mean ± SD). and 110 healthy control group, their ages range between 10-40 years old and 20.1 ± 5.9 year (mean ± SD), these two groups were matched in age and gender. In order to detect c.35delG, 235delC and 167delT mutations in GJB2 gene, we were employed the polymerase chain reaction – restriction fragment length polymorphism (PCR-RFLP) technique.Results: From 95 deaf patients with non syndromic hearing loss (NSHL), were participated in this study. The c.35delG was the main frequent mutation encountered with GJB2 gene, of the 95 patients, 38(40%) were heterozygous and the others 57(60%) were homozygous genotypes. The second degree mutation in GJB2 gene was c.235delC mutation. Which from the 95 deaf patients, 35 (36.8%) were carried out homozygous, 5 (5.3%) were carried out heterozygous and 55(57.9) of the study individuals were appeared wild genotypes. None of the 95 deaf patients were showed the c.167delT mutation, while Connexin 26 studied mutations were not detected in healthy control group.Conclusion: Our data conclude that the GJB2 c.35delG and c.235delC gene mutations were the main cause of congenital hearing loss in Iraqi deaf population.


2021 ◽  
Author(s):  
Anwar Madlool Al-janabi ◽  
Habeeb Shuhaib Ahmmed ◽  
Salih Mahdi Alkhafaji

Abstract Objectives: The ARNSHL wasn’t been studied enough in Iraq, this study aimed to detect the prevalence of the three most common mutations of Connexin 26 gene in Iraqi population. This study was conducted in order to detect c.35delG, c.235delC and c.167delT mutations in GJB2 gene, we were employed PCR-RFLP assays.Results: The current case-control study was conducted from January 2018 to January 2020, The study was included 95 deaf patients (55 males and 40 females) their age range between 11-40 years and 21.5 ± 6.3 year (mean ± SD) and 110 healthy control group, their ages range between 10-40 years and 20.1 ± 5.9 year (mean ± SD), these two groups were matched in age and gender. From 95 deaf patients with ARNSHL who were participated in this study, c.35delG was the main frequent mutation encountered with GJB2 gene, The second frequent mutation was c.235delC, None of 95 deaf patients were showed the c.167delT mutation, these variants were not detected in healthy control group which was studied parallel with patients group. Our data conclude that GJB2 c.35delG and c.235delC gene mutations were the main cause of ARNSHL in Iraqi deaf population.


Gene ◽  
2013 ◽  
Vol 525 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Zied Riahi ◽  
Hassen Hammami ◽  
Houyem Ouragini ◽  
Habib Messai ◽  
Rim Zainine ◽  
...  

Author(s):  
Olga Šterna ◽  
Natālija Proņina ◽  
Ieva Grīnfelde ◽  
Sandra Kušķe ◽  
Astrīda Krūmiņa ◽  
...  

Spectrum and Frequency of the GJB2 Gene Mutations Among Latvian Patients with Prelingual Nonsyndromic Hearing Loss Mutations in the GJB2 gene (connexin 26) are the most common cause of congenital nonsyndromic severe-to-profound hearing loss. Sixty-five hearing impaired probands from Latvia were tested for mutations in the GJB2 gene to determine the percentage of hearing loss attributed to connexin 26 and the types of mutations in this population. A total of 62% of patients tested had GJB2 mutations. Four different mutations in the GJB2 gene were identified in Latvian patients with nonsyndromic sensorineural hearing loss: 35delG, 311-324del14, 235delC and M34T. The most prevalent mutation is 35delG (47% of all probands were homozygous and 8% compound heterozygous). Our findings support the conclusion that the 35delG mutation is the most prevalent GJB2 mutation and that it is the common cause of hereditary nonsyndromic hearing loss in populations of European descent.


2004 ◽  
Vol 118 (1) ◽  
pp. 8-11 ◽  
Author(s):  
Fabrizio Salvinelli ◽  
Manuele Casale ◽  
Luca D’Ascanio ◽  
Luca Firrisi ◽  
Fabio Greco ◽  
...  

35delG is the most common mutation in the Connexin-26 gene, representing a major cause of autosomal recessive hearing loss. The aim of this study was to evaluate the relationship between the audiological phenotype and the 35delG mutation in 64 Sicilians with non-syndromic deafness. Pure-tone audiometry and a screening for 35delG mutation were performed. Audiograms were evaluated according to the classification of Liu and Xu. Thirteen homozygotes and nine heterozygotes for the investigated mutation were found. Symmetrical hearing loss was significantly (p=0.008) more common in homozygous subjects than in those without the Connexin-26 mutation. Profound-severe hypoacusia was found in 92.3 per cent of 35delG homozygous, 22.3 per cent of heterozygous and 58.7 per cent of 35delG absent patients. Residual shape audiograms were more frequent in homozygotes. A molecular analysis for the 35delG mutation should be performed in cases of symmetric, severe-profound congenital hearing loss, as a genetic cause is probable in such cases.


2016 ◽  
Vol 59 (6-7) ◽  
pp. 325-329 ◽  
Author(s):  
Amina Bakhchane ◽  
Amale Bousfiha ◽  
Hicham Charoute ◽  
Sara Salime ◽  
Mustapha Detsouli ◽  
...  

2016 ◽  
Vol 86 (1-2) ◽  
pp. 9-17 ◽  
Author(s):  
Bekir Ucan ◽  
Mustafa Sahin ◽  
Muyesser Sayki Arslan ◽  
Nujen Colak Bozkurt ◽  
Muhammed Kizilgul ◽  
...  

Abstract.The relationship between Hashimoto’s thyroiditis and vitamin D has been demonstrated in several studies. The aim of the present study was to evaluate vitamin D concentrations in patients with Hashimoto’s thyroiditis, the effect of vitamin D therapy on the course of disease, and to determine changes in thyroid autoantibody status and cardiovascular risk after vitamin D therapy. We included 75 patients with Hashimoto’s thyroiditis and 43 healthy individuals. Vitamin D deficiency is defined as a 25-hydroxy vitamin D (25(OH)D3) concentration less than 20ng/mL. Vitamin D deficient patients were given 50.000 units of 25(OH)D3 weekly for eight weeks in accordance with the Endocrine Society guidelines. All evaluations were repeated after 2 months of treatment. Patients with Hashimoto’s thyroiditis had significantly lower vitamin D concentrations compared with the controls (9.37±0.69 ng/mL vs 11.95±1.01 ng/mL, p < 0.05, respectively). Thyroid autoantibodies were significantly decreased by vitamin D replacement treatment in patients with euthyroid Hashimoto’s thyroiditis. Also, HDL cholesterol concentrations improved in the euthyroid Hashimoto group after treatment. The mean free thyroxine (fT4) concentrations were 0.89±0.02 ng/dL in patients with Hashimoto’s thyroiditis and 1.07±0.03 ng/dL in the healthy control group (p < 0.001). The mean thyroid volumes were 7.71±0.44 mL in patients with Hashimoto’s thyroiditis and 5.46±0.63 mL in the healthy control group (p < 0.01). Vitamin D deficiency is frequent in Hashimoto’s thyroiditis and treatment of patients with this condition with Vitamin D may slow down the course of development of hypothyroidism and also decrease cardiovascular risks in these patients. Vitamin D measurement and replacement may be critical in these patients.


2020 ◽  
Vol 22 (9) ◽  
pp. 657-662 ◽  
Author(s):  
Mustafa Celik ◽  
Alper Şen ◽  
İsmail Koyuncu ◽  
Ataman Gönel

Aim and Objective:: To determine the mechanisms present in the etiopathogenesis of nasal polyposis. It is not clear whether amino acids contribute in a causal way to the development of the disease. Therefore, the aim of this study was to determine the plasma-free amino acid profile in patients with nasal polyposis and to compare the results with a healthy control group. Materials and Methods:: This was a prospective controlled study that took place in the Otolaryngology Department at the Harran University Faculty of Medicine between April 2017 and April 2018. Plasmafree amino acid profile levels were studied in serum samples taken from a patient group and a healthy control group. Patients who were diagnosed with bilateral diffuse nasal polyposis and were scheduled for surgical interventions were included in this study. Individuals whose age, gender, and body mass index values were compatible with that of the patient group and who did not have any health problems were included in the control group. All the participants whose levels of plasma-free amino acid were thought to be affected by one or more of the following factors were excluded from the study: smoking and alcohol use, allergic rhinitis presence, the presence of acute or chronic sinusitis, a history of endoscopic sinus surgery, unilateral nasal masses, a history of chronic drug use, systemic or topical steroid use in the last three months for any reason, and liver, kidney, hematological, cardiovascular, metabolic, neurological, or psychiatric disorders or malignancies. Results: In patients with nasal polyposis, 3-methyl histidine (3-MHIS: nasal polyposis group (ng) = 3.22 (1.92 – 6.07); control group (cg) = 1.21 (0.77 – 1.68); p = 0.001); arginine (arg: ng = 98.95 (70.81 – 117.75); cg = 75.10 (54.49 – 79.88); p = 0.005); asparagine (asn: ng = 79.84 (57.50 – 101.44); cg = 60.66 (46.39 – 74.62); p = 0.021); citrulline (cit: ng = 51.83 (43.81 – 59.78); cg = 38.33 (27.81 – 53.73); p = 0.038); cystine (cys: ng = 4.29 (2.43 – 6.66); cg = 2.41 (1.51 – 4.16); p = 0.019); glutamic acid (glu: ng = 234.86 (128.75 – 286.66); cg = 152.37 (122.51 – 188.34); p = 0.045); histidine (his: ng = 94.19 (79.34 – 113.99); cg = 74.80 (62.76 – 98.91); p = 0.018); lysine (lys: ng = 297.22 (206.55 – 371.25); cg = 179.50 (151.58 – 238.02); p = 0.001); ornithine (ng = 160.62 (128.36 – 189.32); cg = 115.91 (97.03 – 159.91); p = 0.019); serine (ser: ng = 195.15 (151.58 – 253.07); cg = 83.07 (67.44 – 92.44); p = 0.001); taurine (tau: ng = 74.69 (47.00 – 112.13); cg = 53.14 (33.57 – 67.31); p = 0.006); tryptophan (trp: ng = 52.31 (33.81 – 80.11); cg = 34.44 (25.94 – 43.07); p = 0.005), homocitrulline (ng = 1.75 (1.27 – 2.59); cg = 0.00 (0.00 – 0.53); p = 0.001); norvaline (ng = 6.90 (5.61 – 9.18); cg = 4.93 (3.74 – 7.13); p = 0.021); argininosuccinic acid (ng = 14.33 (10.06 – 25.65); cg = 12.22 (5.77 – 16.87) p = 0.046); and plasma concentrations were significantly higher than in the healthy control group (p <0.05). However, the gamma-aminobutyric acid (gaba: ng = 0.16 (0.10 – 0.24); cg = 0.21 (0.19 – 0.29); p = 0.010) plasma concentration was significantly lower in the nasal polyposis group than in the healthy control group. Conclusion: In this study, plasma levels of 15 free amino acids were significantly higher in the nasal polyposis group than in the healthy control group. A plasma level of 1 free amino acid was found to be significantly lower in the nasal polyposis group compared to the healthy control group. Therefore, it is important to determine the possibility of using the information obtained to prevent the recurrence of the condition and to develop effective treatment strategies. This study may be a milestone for studies of this subject. However, this study needs to be confirmed by further studies conducted in a larger series.


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