• Title/Summary/Keyword: GJB1

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Genetics of Hearing Loss in North Iran Population: An Update of Spectrum and Frequency of GJB2 Mutations

  • Koohiyan, Mahbobeh;Azadegan-Dehkordi, Fatemeh;Koohian, Farideh;Hashemzadeh-Chaleshtori, Morteza
    • Journal of Audiology & Otology
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    • v.23 no.4
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    • pp.175-180
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    • 2019
  • Diagnosis of pre-lingual hearing loss (HL) is difficult owing to the high number of genes responsible. The most frequent cause of HL is DFNB1 due to mutations in the GJB2 gene. It represents up to 40% of HL cases in some populations. In Iran, it has previously been shown that DFNB1 accounts for 16-18% of cases but varies among different ethnic groups. Here, we reviewed results from our three previous publications and data from other published mutation reports to provide a comprehensive collection of data for GJB2 mutations and HL in northern Iran. In total, 903 unrelated families from six different provinces, viz., Gilan, Mazandaran, Golestan, Ghazvin, Semnan, and Tehran, were included and analyzed for the type and prevalence of GJB2 mutations. A total of 23 different genetic variants were detected from which 18 GJB2 mutations were identified. GJB2 mutations were 20.7% in the studied northern provinces, which was significantly higher than that reported in southern populations of Iran. Moreover, a gradient in the frequency of GJB2 mutations from north to south Iran was observed. c.35delG was the most common mutation, accounting for 58.4% of the cases studied. This study suggests that c.35delG mutation in GJB2 is the most important cause of HL in northern Iran.

Genetics of Hearing Loss in North Iran Population: An Update of Spectrum and Frequency of GJB2 Mutations

  • Koohiyan, Mahbobeh;Azadegan-Dehkordi, Fatemeh;Koohian, Farideh;Hashemzadeh-Chaleshtori, Morteza
    • Korean Journal of Audiology
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    • v.23 no.4
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    • pp.175-180
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    • 2019
  • Diagnosis of pre-lingual hearing loss (HL) is difficult owing to the high number of genes responsible. The most frequent cause of HL is DFNB1 due to mutations in the GJB2 gene. It represents up to 40% of HL cases in some populations. In Iran, it has previously been shown that DFNB1 accounts for 16-18% of cases but varies among different ethnic groups. Here, we reviewed results from our three previous publications and data from other published mutation reports to provide a comprehensive collection of data for GJB2 mutations and HL in northern Iran. In total, 903 unrelated families from six different provinces, viz., Gilan, Mazandaran, Golestan, Ghazvin, Semnan, and Tehran, were included and analyzed for the type and prevalence of GJB2 mutations. A total of 23 different genetic variants were detected from which 18 GJB2 mutations were identified. GJB2 mutations were 20.7% in the studied northern provinces, which was significantly higher than that reported in southern populations of Iran. Moreover, a gradient in the frequency of GJB2 mutations from north to south Iran was observed. c.35delG was the most common mutation, accounting for 58.4% of the cases studied. This study suggests that c.35delG mutation in GJB2 is the most important cause of HL in northern Iran.

Study on the Effect of Gwanjulbang-5 in Rheumatoid Arthritis (관절 5호방의 류마토이드 관절염 치료효과에 대한 실험적 연구)

  • Choi, Jae-Young;Heo, Dong-Seok;Yoon, Il-Ji;Oh, Min-Seok
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.3
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    • pp.728-735
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    • 2007
  • This study was carried out to know the effect of Gwanjulbang-5(hereinafter refer to GJB-5) to on Rheumatoid Arthritis by using human fibroblast-like synoviocytes(hFLS). We performed several experimetal items : that is cytotoxicity of GJB-5, mRNA expression of pro-imflammatory cytokines in hFLS and production of NO, ROS. The results were obtained as follows : GJB-5 reduced the production of pro-inflammatory cytokines TNF-${\alpha}$, IL-1${\beta}$, IL-6, IL-8 in hFLS, increased the production of TIMP-1. As well as GJB-5 reduced the production of ICAM-1, MMP-3, NOS-II, the production of NO and ROS, and the proliferation of hFLS in proportion to the concentration of GJB-5. In conclusion, these results shows that GJB-5 had immunomodulatory effects in treating rheumatoid arthritis.

Population-Based Newborn Hearing Impairment Screening Test Using GJB2 Mutation Analysis

  • Lee, Kyung-Ok;Jeong, Su-Jin;Byun, Ji-Young;Kim, Jeong-Sook;Lee, Hye-Jung;Seong, Hye-Soon;Kim, Kyung-Tae
    • Korean Journal of Clinical Laboratory Science
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    • v.39 no.2
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    • pp.113-121
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    • 2007
  • Hearing loss is a common congenital disorder that is frequently associated with mutations in the Cx26 gene (GJB2). Recently, the mutation analysis of GJB2 has been used in a newborn screening test for the detection of hearing impairment. Population-based studies should be performed before the application of genetic testing for the identification of deaf newborns. In this study, 8 positions of GJB2 mutations-including 35delG, 167delT, 235delC, V27I, V37I, M34T, E114G, and I203T-were analyzed using PCR-direct sequencing in a total of 437 healthy Korean neonates. DNAs from dried blood spots were extracted using a commercial DNA extraction kit. The PCR-amplified products (783 bps) of the GJB2 gene were detected using 2% agarose gel electrophoresis and subjected to direct sequencing. The sequences were compared with those in the GenBank database by using the BLAST program. In this study, 5 GJB2 mutations -including V27I (79G>A), V37I (109G>A), E114G (341A>G), I203T (608T>C), and 235delC- were found. Of the 437 neonate samples, 301 subjects showed GJB2 mutations (68.9%, 301/437). The V27I mutation was found in 271 subjects and was the most frequent (62.0%, 271/437). The E114G, I203T and V37I mutations were shown in 146, 17 and 14 subjects, respectively. The 235delC mutation was found in 1 subject. The E114G mutation was frequently accompanied by the V27I mutation. V27I/E114G (97.2%, 143/147) was the most common double mutation and 3 subjects had the double mutation V27I/I203T. A triple mutation, V27I/E114G/I203T, was found in 1 subject. In conclusion, PCR-direct sequencing is a convenient tool for the rapid detection of GJB2 mutations and this data might provide information for the genetic counseling of the GJB2 gene.

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Suppressive Effect of GJB-7 on Collagen-Induced Arthritis in Mice (관절7호방이 Type II collagen으로 유발된 흰쥐의 관절염에 미치는 영향)

  • Min, Boo-Ki;Oh, Min-Seok
    • The Journal of Korean Medicine
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    • v.31 no.4
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    • pp.63-78
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    • 2010
  • Objectives: This study was carried out to know the effects of Gwan-Jul-Bang-7 (hereafter referred to GJB-7) on the inhibition of arthritis induced by collagen on the mouse. Methods: To assess the effects of GJB-7 on mouse with arthritis induced by collagen II, we conducted several experiments such as analysis of cytotoxicity, hepatotoxicity, arthritis index, total cell number of draining lymph nodes and paw joints, value of immunocyte in PBMC (peripheral blood mononuclear cell), DLN (draining lymph node) and paw joint, measurement of cytokine and anti-collagen II, observation of the histological changes of joint. Results: 1. Cytotoxicity against HFC (human fibroblast cells) was not observed in any concentration and hepatotoxicity was not observed in the GJB-7 treated group. 2. The incidence of arthritis significantly decreased. 3. Total cell number of draining lymph nodes significantly increased and total cell number of paw joints significantly decreased. 4. The percentage of $CD8^+$ cells in PBMC (peripheral blood mononuclear cell) significantly increased. The percentage of $CD3^+/CD69^+$, and $CD3^+/CD49b^+$ cells in PBMC significantly decreased. 5. The percentage of $CD19^+,\;CD3^+$, and $CD4^+/CD25^+$ cells in DLN (draining lymph nodes) significantly increased. The percentage of $B220^+/CD23^+$ cells in DLN significantly decreased. 6. The percentage of $CD3^+,\;CD4^+$, and $CD11b^+/Gr-1^+$ cells in paw joints significantly decreased. 7. The production of TNF-$\alpha$, IL-6, and MCP-1 significantly decreased. 8. Anti-collagen II in serum significantly decreased. 9. With the hematoxylin and eosin stain, inflammation of joint decreased. Under Masson's trichrome stain, the cartilage destruction and synovial cell proliferation and the expression of collagen fibers decreased. Conclusions: Comparison of the results for this study showed that GJB-7 had immunomodulatory effects. So we expect that GJB-7 could be used as an effective drug for not only rheumatoid arthritis but also another auto-immune diseases.

X-linked Charcot-Marie-Tooth disease case with a novel missense mutation in GJB1 gene

  • Lee, Jong-Mok;Shin, Jin-Hong
    • Journal of Genetic Medicine
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    • v.15 no.2
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    • pp.107-109
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    • 2018
  • X-linked Charcot-Marie-Tooth disease type 1 (CMTX1) is caused by the mutation in GJB1 gene, characterized by the transient central nervous system involvement and long standing peripheral polyneuropathy which does not fulfill the criteria of demyelination or axonopathy. We describe a 37-year-old man with progressive bilateral leg weakness since his early teen. He suffered transient right hemiparesis, followed by quadriparesis at 14 years of age. When we examined him at 37 years of age, he presented a distal muscle weakness on lower extremities with a sensory symptom. The nerve conduction study demonstrated a motor conduction velocity between 26 and 49 m/s. The whole exome sequencing revealed a novel variant c.136 G>A in GJB1. This report will raise awareness in this rare disease, which is frequently misdiagnosed early in its course.

Mutations in GJB2 as Major Causes of Autosomal Recessive Non-Syndromic Hearing Loss: First Report of c.299-300delAT Mutation in Kurdish Population of Iran

  • Azadegan-Dehkordi, Fatemeh;Bahrami, Tayyebe;Shirzad, Maryam;Karbasi, Gelareh;Yazdanpanahi, Nasrin;Farrokhi, Effat;Koohiyan, Mahbobeh;Tabatabaiefar, Mohammad Amin;Hashemzadeh-Chaleshtori, Morteza
    • Journal of Audiology & Otology
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    • v.23 no.1
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    • pp.20-26
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    • 2019
  • Background and Objectives: Autosomal recessive non-syndromic hearing loss (ARNSHL) with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations in gap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find the contribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHL cases in the Kurdish population. Subjects and Methods: Genomic DNA was extracted from a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markers linked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families were linked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmation linkage analysis (to perform a large project). Results: A total of three different mutations were determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previously reported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygous pathogenic mutations of GJB2 gene was observed in nine out of the 45 families (20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observed in 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutations was less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions: Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL in Iran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in this population.

Mutations in GJB2 as Major Causes of Autosomal Recessive Non-Syndromic Hearing Loss: First Report of c.299-300delAT Mutation in Kurdish Population of Iran

  • Azadegan-Dehkordi, Fatemeh;Bahrami, Tayyebe;Shirzad, Maryam;Karbasi, Gelareh;Yazdanpanahi, Nasrin;Farrokhi, Effat;Koohiyan, Mahbobeh;Tabatabaiefar, Mohammad Amin;Hashemzadeh-Chaleshtori, Morteza
    • Korean Journal of Audiology
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    • v.23 no.1
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    • pp.20-26
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    • 2019
  • Background and Objectives: Autosomal recessive non-syndromic hearing loss (ARNSHL) with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations in gap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find the contribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHL cases in the Kurdish population. Subjects and Methods: Genomic DNA was extracted from a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markers linked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families were linked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmation linkage analysis (to perform a large project). Results: A total of three different mutations were determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previously reported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygous pathogenic mutations of GJB2 gene was observed in nine out of the 45 families (20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observed in 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutations was less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions: Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL in Iran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in this population.

A case of X-linked Charcot-Marie-tooth disease type 1 manifesting as recurrent alternating hemiplegia with transient cerebral white matter lesions

  • Kang, Minsung;Hwang, Sun-Jae;Shin, Jin-Hong;Kim, Dae-Seong
    • Annals of Clinical Neurophysiology
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    • v.23 no.2
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    • pp.130-133
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    • 2021
  • X-linked Charcot Marie Tooth disease type 1 (CMTX1) is a clinically heterogenous X-linked hereditary neuropathy caused by mutation of the gene encoding gap junction beta 1 protein (GJB1). Typical clinical manifestations of CMTX1 are progressive weakness or sensory disturbance due to peripheral neuropathy. However, there have been some CMTX1 cases with accompanying central nervous system (CNS) manifestations. We report the case of a genetically confirmed CMTX1 patient who presented recurrent transient CNS symptoms without any symptom or sign of peripheral nervous system involvement.

Suppressive Effect of Kwanjulbang-6 on Collagen-Induced Arthritis in Mice (관절6호방이 Type II collagen으로 유발된 관절염에 미치는 영향)

  • Kim, Hyun-Soo;Hong, Seo-Young;Heo, Dong-Seok;Oh, Min-Suck
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.5
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    • pp.1003-1011
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    • 2009
  • This study was carried out to know the effects of Kwanjulbang-6(GJB-6) on the inhibition of arthritis. GJB-6 was orally administered to mouse with arthritis induced by collagen II . Cytotoxicity, hepatotoxicity, arthritis index, value of immunocyte in draining lymph node and paw joint, rheumatoid factor in serum were measured in vivo. The incidence of arthritis was significantly decreased. Total cell number of draining lymph node was significantly increased compared with control. Total cell number of paw joint was significantly decreased compared with control. The absolute number of $CD19^+$, $CD8^+$, $CD3^+/CD69^+$, $CD3^+/CD49b^+$, $CD4^+/CD44^+$, $CD3^+$, $CD4^+$, $CD4^+/CD25^+$ and $CD3^+/CD8^+$ cells in draining lymph node were significantly increased compared with control. The absolute number of $CD3^+$, $CD4^+$, $CD4^+/CD25^+$ and $CD11b^+/Gr-1^+$ cells in paw joint were significantly decreased compared with control. The absolute number of $B220^+/CD23^+$ and $MHCII^+/CD11c^+$ cell in draining lymph node were significantly decreased compared with control. The levels of IgG was decreased and The levels of IgM was significantly decreased compared with control. Anti-collagen II in serum was significantly decreased compared with control. With the hematoxylin and eosin stain, the cartilage destruction and synovial cell proliferation were decreased compared with control. With the Masson's trichrome stain, the expression of collagen fibers was decreased compared with control. Results showed that GJB-6 had immunomodulatory effects. So we expect that GJB-6 should be used as a effective drugs for not only rheumatoid arthritis but also another auto-immune disease.