• 제목/요약/키워드: GJB2

검색결과 11건 처리시간 0.023초

The Spectrum of GJB2 Mutations in Korean Patients with Genetic Hearing Loss: a Functional Study and Study of Cell Growth Control by Dominant Type of GJB2 Mutants

  • Jin, Hyun-Seok;Kim, Jong-Bae;Go, Sang-Hee;Lee, Mi-Young;Jung, Sung-Chul;Park, Hyun-Young;Park, Hong-Joon;Koo, Soo-Kyung
    • 대한의생명과학회지
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    • 제12권4호
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    • pp.311-318
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    • 2006
  • The GJB2 mutation is mostly recessive in non-syndromic hearing loss, but specific mutations display a dominant type and syndromic hearing impairment. Both U54K and R75Q mutations present a dominant type in pedigrees with associated skin disorders. The purpose of this study was to investigate whether two GJB2 mutations can exhibit a dominant-negative effect on the growth abrogation and the gap junctional intercellular communication capacity exerted by wild-type connexin 26. A specific mutant region of GJB2 showed a loss of gap junction activity and a dominant negative effect on wild-type GJB2. The two mutants exerted a dominant-negative effect on the GJIC capacity and have independently effected GJB2 regulated growth of Hela cells; however, they have no dominant-negative growth effect on wild-type GJB2. It is proposed that the different mechanisms of the dominant-negative effect on wild-type GJB2 involve cell growth and GJIC function. This study describes mutations found in Korean deaf patients and that are typical of other east Asian regions.

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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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    • 제23권4호
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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
    • 대한청각학회지
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    • 제23권4호
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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.

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
    • 대한임상검사과학회지
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    • 제39권2호
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    • pp.113-121
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    • 2007
  • 선천성난청은 비교적 흔한(1/1,000) 유전성질환으로 여러 유전자와 관련이 있으며, 최근에는 connexin 26 단백질내의 GJB2 유전자 돌연변이와의 관련성이 보고되고 있다. 유전질환을 예측하기 위한 유전자선별검사를 임상에 적용하기 위해서는 각 해당 국가별로 정상인에서 유전자돌연변이의 빈도를 구하고, 환자의 결과를 비교하여 활용성을 검토한 후 사용하여야 한다. 본 연구에서는 청력검사(TEOAE)가 정상인 신생아에서 GJB2 유전자 돌연변이 빈도를 구하여 screening test를 위한 한국인의 database를 수립하고자 하였다. 검체로는 437 명의 건강한 신생아의 발꿈치를 천자하여 얻은 혈액을 이용하였고, DNA는 Intron 사의 킷트를 사용하여 추출하였으며, GJB2 PCR을 실시한 후 증폭산물(783 bps)은 2% agarose gel로 전기영동을 실시하였고, DNA 자동염기서열분석기를 이용하여 분석을 실시하였다. 총 437명의 한국인 신생아에서 GJB2 유전자 중 8곳의 돌연변이(35delG, 167delT, 235delC, V27I, V37I, M34T, E114G, I203T)를 분석하였으며, 이 중 5곳에서 돌연변이가 발견되었다. 총 437명 중 301명(68.9%)에서 GJB2 유전자돌연변이가 발견되었는데, 그 중 154명이 단일돌연변이였다. V27I 변이가 271명으로 가장 많이 발견되었으며, 대부분의 V27I 변이는 E114G 변이와 함께 나타났다. E114G 변이는 총 146명, I203T 변이는 17명, V37I 변이는 14명, 235delC 변이는 1명의 순으로 나타났다. 이중돌연변이의 대부분은 V27I/E114G였으며, V27I/I203T는 3명에서 나타났고, 삼중돌연변이 V27I/E114G/I203T는 1명에서 발견되었다. 본 연구결과, PCR을 이용한 자동염기분석검사는 GJB2 유전자의 돌연변이 검출에 매우 유용하며, 본 결과는 향 후 신생아 난청선별검사를 위한 한국인의 database로 활용될 수 있을 것으로 사료된다.

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

  • 민부기;오민석
    • 대한한의학회지
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    • 제31권4호
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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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    • 제15권2호
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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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    • 제23권1호
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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
    • 대한청각학회지
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    • 제23권1호
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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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    • 제23권2호
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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.

Ultimate strength of rectangular concrete-filled steel tubular (CFT) stub columns under axial compression

  • Huang, Yan-Sheng;Long, Yue-Ling;Cai, Jian
    • Steel and Composite Structures
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    • 제8권2호
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    • pp.115-128
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    • 2008
  • A method is proposed to estimate the ultimate strength of rectangular concrete-filled steel tubular (CFT) stub columns under axial compression. The ultimate strength of concrete core is determined by using the conception of the effective lateral confining pressure and a failure criterion of concrete under true triaxial compression, which takes into account the difference between the lateral confining pressure provided by the broad faces of the steel tube and that provided by the narrow faces of the steel tube. The longitudinal steel strength of broad faces and that of the narrow faces of the steel tube are calculated respectively due to that buckling tends to occur earlier and more extensively on the broader faces. Finally, the proposed method is verified with experimental results. Corresponding values of ultimate strength calculated by ACI (2005), AISC (1999) and GJB4142-2000 are given respectively for comparison. It is found from comparison that the proposed method shows a good agreement with the experimental results.