• Title/Summary/Keyword: gene mutations

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Identification of Genetic Causes of Inherited Peripheral Neuropathies by Targeted Gene Panel Sequencing

  • Nam, Soo Hyun;Hong, Young Bin;Hyun, Young Se;Nam, Da Eun;Kwak, Geon;Hwang, Sun Hee;Choi, Byung-Ok;Chung, Ki Wha
    • Molecules and Cells
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    • v.39 no.5
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    • pp.382-388
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    • 2016
  • Inherited peripheral neuropathies (IPN), which are a group of clinically and genetically heterogeneous peripheral nerve disorders including Charcot-Marie-Tooth disease (CMT), exhibit progressive degeneration of muscles in the extremities and loss of sensory function. Over 70 genes have been reported as genetic causatives and the number is still growing. We prepared a targeted gene panel for IPN diagnosis based on next generation sequencing (NGS). The gene panel was designed to detect mutations in 73 genes reported to be genetic causes of IPN or related peripheral neuropathies, and to detect duplication of the chromosome 17p12 region, the major genetic cause of CMT1A. We applied the gene panel to 115 samples from 63 non-CMT1A families, and isolated 15 pathogenic or likelypathogenic mutations in eight genes from 25 patients (17 families). Of them, eight mutations were unreported variants. Of particular interest, this study revealed several very rare mutations in the SPTLC2, DCTN1, and MARS genes. In addition, the effectiveness of the detection of CMT1A was confirmed by comparing five 17p12-nonduplicated controls and 15 CMT1A cases. In conclusion, we developed a gene panel for one step genetic diagnosis of IPN. It seems that its time- and cost-effectiveness are superior to previous tiered-genetic diagnosis algorithms, and it could be applied as a genetic diagnostic system for inherited peripheral neuropathies.

BRCA1 Gene Mutations and Influence of Chemotherapy on Autophagy and Apoptotic Mechanisms in Egyptian Breast Cancer Patients

  • Abdel-Mohsen, Mohamed Ahmed;Ahmed, Omiama Ali;El-Kerm, Yasser Mostafa
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1285-1292
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    • 2016
  • Background: It is well established that mutations in the BRCA1 gene are a major risk factor for breast cancer. Induction of cancer cell death and inhibition of survival are the main principles of cancer therapy. In this context, autophagy may have dual roles in cancer, acting on the one hand as a tumor suppressor and on the other as a mechanism of cell survival that can promote the growth of established tumors. Therefore, understanding the role of autophagy in cancer treatment is critical. Moreover, defects in apoptosis, programmed cell death, may lead to increased resistance to chemotherapy. Purpose: The aim of the present study was to detect BRCA1 gene mutations in order to throw more light on their roles as risk factors for breast cancer in Egypt. Secondly the role of autophagy and apoptosis in determining response to a fluorouracil, doxorubicin, cyclophosphamide (FAC) regimen was investigated. Materials and Methods: Forty-five female breast cancer cases and thirty apparently healthy females were enrolled in the present study. Serum levels of autophagic biomarkers, Beclin 1 and LC3 as well as the serum levels of apoptosis biomarkers Bcl-2 and Caspase-3 were measured before and after chemotherapy. Results: BRCA1 mutations were found in 5 (16.7%) and 44 (99.8%) of the controls and cancer patients, the most frequent being 5382insC followed by C61G and 185 delAG. The results revealed that chemotherapy caused elevation in serum concentration levels of the autophagic biomarkers (Beclin 1 and LC3). This elevation was associated with a significant decrease in serum concentration levels of Bcl-2 and significant increase in caspase-3 concentration levels (apoptotic markers). Conclusions: The results of the present study indicate a very high level of BRCA mutations in breast cancer cases in Egypt and point to involvement of autophagic and apoptotic machinery activation in response to FAC chemotherapy.

Clinical Features of Lung Cancer in Japanese Patients Aged Under 50

  • Igata, Fumiyasu;Uchino, Junji;Fujita, Masaki;Iwasaki, Akinori;Watanabe, Kentaro
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3377-3380
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    • 2016
  • The proportion of lung cancer patients under 50 years old is small at approximately 5-10%, but as with patients older than 50, the number is on the rise. Although lung cancer treatment strategies have undergone extensive transformation in recent years based on the presence or absence of oncogenic driver mutations, there are few reports regarding these mutations in the young or the relationship between clinical setting and prognosis. Therefore, we conducted a study of clinical features in 36 patients under the age of 50 who were diagnosed with primary lung cancer from October 2008 to November 2015. The 22 patients in stages I through III A underwent operations, and all 17 whose lung cancer were detected through screening were candidates for surgery. Gene analysis was conducted for 26 (72.2%); 10 (38.5%) were positive for EGFR gene mutations, and ALK gene translocation was present in 4 (15.4%). In stage IV patients, the median progression free survival (PFS) in the ALK translocation positive and negative patients was 518 days and 130 days, respectively, and the median overall survival (OS) was not reached and 280 days, respectively. A trend toward extended PFS (p=0.203) and OS (p=0.056) was observed in patients positive for ALK translocation. We must strive for early detection by increasing screening rates and evaluate oncogenic driver mutations important for prognosis of lung cancer in the young.

Successful sulfonylurea treatment in a patient with permanent neonatal diabetes mellitus with a novel KCNJ11 mutation

  • Ahn, Sung Yeon;Kim, Gu-Hwan;Yoo, Han-Wook
    • Clinical and Experimental Pediatrics
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    • v.58 no.8
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    • pp.309-312
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    • 2015
  • Permanent neonatal diabetes mellitus refers to diabetes that occurs before the age of 6 months and persists through life. It is a rare disorder affecting one in 0.2-0.5 million live births. Mutations in the gene KCNJ11, encoding the subunit Kir6.2, and ABCC8, encoding SUR1 of the ATP-sensitive potassium ($K_{ATP}$) channel, are the most common causes of permanent neonatal diabetes mellitus. Sulfonylureas close the $K_{ATP}$ channel and increase insulin secretion. KCNJ11 and ABCC8 mutations have important therapeutic implications because sulfonylurea therapy can be effective in treating patients with mutations in the potassium channel subunits. The mutation type, the presence of neurological features, and the duration of diabetes are known to be the major factors affecting the treatment outcome after switching to sulfonylurea therapy. More than 30 mutations in the KCNJ11 gene have been identified. Here, we present our experience with a patient carrying a novel p.H186D heterozygous mutation in the KCNJ11 gene who was successfully treated with oral sulfonylurea.

A Case of Glycogen Storage Disease IV with Rare Homozygous Mutations in the Glycogen Branching Enzyme Gene

  • Choi, So Yoon;Kang, Ben;Choe, Jae Young;Lee, Yoon;Jang, Hyo Jeong;Park, Hyung-Doo;Lee, Suk-Koo;Choe, Yon Ho
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.21 no.4
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    • pp.365-368
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    • 2018
  • Glycogen storage disease (GSD) IV is a rare autosomal recessive inherited disorder caused by mutations in the gene coding for glycogen branching enzyme leading to progressive liver disease. GSD IV is associated with mutations in GBE1, which encodes the glycogen branching enzyme. We report a case of GSD IV with rare homozygous mutations in the GBE1 gene (c.791G>A (p.Gly264Glu), which was successfully treated by liver transplantation.

High Frequency of Codon 12 but not Codon 13 and 61 K-ras Gene Mutations in Invasive Ductal Carcinoma of Breast in a South Indian Population

  • Sushma, C;Prasad, Shiva;Devi, Rudrama;Murthy, Sudha;Rao, TS;Naidu, CK
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3505-3508
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    • 2015
  • Background: Ras genes are thought to play an important role in human cancer since they have been found to be activated frequently in several types of tumors including breast cancer, where the overall incidence of K-RAS oncogene activation is 0-10%. Evaluation of K-RAS gene not only for mutational frequency but also for mutation types in this downstream signaling gene pathway is necessary to determine the mechanisms of action. The present study was conducted to test the hypothesis that K-RAS activation is involved in breast cancer risk of south Indian population. Materials and Methods: A total of 70 paired pathologically confirmed tumor and non-tumor tissues from the same breast cancer patients were analysed for most common K-RAS mutations of codon 12,13 and 61 by polymerase chain reaction followed by restriction digestion and direct nucleotide sequencing method. Results: We found that a high rate of homozygous and heterozygous mutations of codon 12, but not codon 13 and 61, may influence the invasive ductal carcinoma of breast risk in this study. Conclusions: Our study indicated that only codon 12 may be involved in initiating breast carcinogenesis in India.

Overexpression and Selective Anticancer Efficacy of ENO3 in STK11 Mutant Lung Cancers

  • Park, Choa;Lee, Yejin;Je, Soyeon;Chang, Shengzhi;Kim, Nayoung;Jeong, Euna;Yoon, Sukjoon
    • Molecules and Cells
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    • v.42 no.11
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    • pp.804-809
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    • 2019
  • Oncogenic gain-of-function mutations are clinical biomarkers for most targeted therapies, as well as represent direct targets for drug treatment. Although loss-of-function mutations involving the tumor suppressor gene, STK11 (LKB1) are important in lung cancer progression, STK11 is not the direct target for anticancer agents. We attempted to identify cancer transcriptome signatures associated with STK11 loss-of-function mutations. Several new sensitive and specific gene expression markers (ENO3, TTC39C, LGALS3, and MAML2) were identified using two orthogonal measures, i.e., fold change and odds ratio analyses of transcriptome data from cell lines and tissue samples. Among the markers identified, the ENO3 gene over-expression was found to be the direct consequence of STK11 loss-of-function. Furthermore, the knockdown of ENO3 expression exhibited selective anticancer effect in STK11 mutant cells compared with STK11 wild type (or recovered) cells. These findings suggest that ENO3-based targeted therapy might be promising for patients with lung cancer harboring STK11 mutations.

Rifabutin Susceptibility and rpoB Gene Mutations in Multi-drug Resistant Mycobacterium Tuberculosis (다제내성 결핵균에서 Rifabutin감수성과 rpoB 유전자 돌연변이 양상의 비교 연구)

  • Shim, Tae-Sun;Kim, Jin-Sub;Park, Mi-Sun;Lim, Chae-Man;Lee, Sang-Do;Koh, Youn-Suck;Kim, Woo-Sung;Kim, Dong-Soon;Kim, Won-Dong
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.6
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    • pp.853-869
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    • 2000
  • Background : Following several decades of decline, the incidence of tuberculosis has recent1y begun to increase in many countries of this the control of this disease has been impeded by the emergence of multi-drug resistant tuberculosis (MDR-TB). The development of rapid diagnostic methods and effective new drugs are needed to control MDR-TB. One of the new drugs for MDR-TB is rifabutin (RBU) which has been known to be effective in some patients with MDR-TB. A few reports showed that some types of mutations of the rpoB gene, which were known to be present in 96-98% of rifampicin-resistant M. tuberculosis, were associated with the rifampicin-resistant but RBU-susceptible phenotype. This study was performed to investigate the correlation between RBU susceptibility and the patterns of rpoB gene mutations in Korean MDR-TB. Methods : Sixty-five clinical isolates of multi-drug resistant Mycobacterium tuberculosis, gathered from patients who visited the Asan Medical Center from July 1997 to June 1999, were investigated. Clinical responses to rifabutin-containing regimen were evaluated. An RBU susceptibility test and sequencing analysis of rpoB gene were performed, and the results were analyzed to confirm which mutations correlated with RBU-susceptible MDR-TB. Results : Fifty-three of 56 (95%) clinical isolates of MDR-TB had 60 mutations of the rpoB gene. The most frequent mutations were found at codon 531 (43%), and two mutations were combined in seven clinical isolates. Five of 53 (10%) clinical isolates showed the RBU-susceptible phenotype, and in them the characteristic patterns of point mutations were found at codon 509, 516, and 526. Conclusion : The frequency and pattern of mutations of the rpoB gene of Korean MDR-TB isolates were similar to those in western countries, where the prevalence of tuberculosis is low, but some show RBU-susceptible phenotypes. RBU-susceptible MDR-TB isolates showed the characteristic pattern of mutations of the rpoB gene which could be used to rapidly diagnose RBU susceptibility.

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Coexisting JAK2V617F and CALR Exon 9 Mutations in Myeloproliferative Neoplasms - Do They Designate a New Subtype?

  • Ahmed, Rifat Zubair;Rashid, Munazza;Ahmed, Nuzhat;Nadeem, Muhammad;Shamsi, Tahir Sultan
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.923-926
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    • 2016
  • The classic BCR-ABL1-negative myeloproliferative neoplasm is an operational sub-category of MPNs that includes polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The JAK2V617F mutation is found in ~ 95% of PV and 50-60% of ET or PMF. In most of the remaining JAK2V617F-negative PV cases, JAK2 exon 12 mutations are present. Amongst the JAK2V617F-negative ET or PMF 5-10% of patients carry mutations in the MPL gene. Prior to 2013, there was no specific molecular marker described in the remaining 30-40% ET and PMF. In December 2013, two research groups independently reported mutations in the gene CALR found specifically in ET (67-71%) and PMF (56-88%) but not in PV. Initially CALR mutations were reported mutually exclusive with JAK2 or MPL. However, co-occurrence of CALR mutations with JAK2V617F has been reported recently in a few MPN cases. Many studies have reported important diagnostic and prognostic significance of CALR mutations in ET and PMF patients and CALR mutation screening has been proposed to be incorporated into WHO diagnostic criteria for MPN. It is suggestive in diagnostic workup of MPN that CALR mutations should not be studied in MPN patients who carry JAK2 or MPL mutations. However JAK2V617F and CALR positive patients might have a different phenotype and clinical course, distinct from the JAK2-positive or CALR-positive subgroups and identification of the true frequency of these patients may be an important factor for defining the prognosis, risk factors and outcomes for MPN patients.

Distribution of KRAS and BRAF Mutations in Metastatic Colorectal Cancers in Turkish Patients

  • Gorukmez, Orhan;Yakut, Tahsin;Gorukmez, Ozlem;Sag, Sebnem Ozemri;Karkucak, Mutlu;Kanat, Ozkan
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1175-1179
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    • 2016
  • The results of this study demonstrate the potential prognostic and predictive values of KRAS and BRAF gene mutations in patients with colorectal cancer (CRC). It has been proven that KRAS and BRAF mutations are predictive biomarkers for resistance to anti-EGFR monoclonal antibody treatment in patients with metastatic CRC (mCRC). We demonstrated the distribution of KRAS (codons 12, 13 and 61) and BRAF (codon 600) gene mutations in 50 mCRCs using direct sequencing and compared the results with clinicopathological data. KRAS and BRAF mutations were identified in 15 (30%) and 1 (2%) patients, respectively. We identified KRAS mutations in codon 12, 13 and 61 in 73.3% (11/15), 20% (3/15) and 6.67% (1/15) of the positive patients, respectively. The KRAS mutation frequency was significantly higher in tumors located in the ascending colon (p=0.043). Thus, we found that approximately 1/3 of the patients with mCRC had KRAS mutations and the only clinicopathological factor related to this mutation was tumor location. Future studies with larger patient groups should yield more accurate data regarding the molecular mechanism of CRC and the association between KRAS and BRAF mutations and clinicopathological features.