KHẢO SÁT ĐA HÌNH GEN SOD2 C47T VÀ CAT C262T Ở NAM GIỚI VÔ SINH NGUYÊN PHÁT

Mục tiêu nghiên cứu: Xác định tỷ lệ đa hình gen SOD2 C47T và CAT C262T ở nam giới vô sinh nguyên phát bằng kỹ thuật ARMS-PCR, bước đầu xác định mối liên quan giữa đa hình gen SOD2 C47T và CAT C262T với vô sinh nam. Đối tượng và phương pháp nghiên cứu: Áp dụng kỹ thuật ARMS-PCR để xác định đa hình gen SOD2C47T và CAT C262T ở 42 nam giới vô sinh nguyên phát có mật độ tinh dịch < 15 triệu tinh trùng/ml và 58 nam giới bình thường có ít nhất 1 con <5 tuổi. Kết quả nghiên cứu: Tỷ lệ kiểu gen SOD2 CC/TC/TT ở nhóm nam giới vô sinh lần lượt là 28.5%, 40.5%, 31%;tỷ lệ kiểu gen SOD2 CC/TC/TT ở nhóm chứng lần lượt là 29.3%, 46.6%, 24.1%; sự khác biệt giữa 2 nhóm là không có ý nghĩa thống kê với p>0.05; tỷ lệ mang kiểu gen CAT CC/TC/TT ở nhóm nam giới vô sinh lần lượt là 54.7%,42.9% và 2.4%;tỷ lệ mang kiểu gen CAT CC/TC/TT ở nhóm bình thường là 77.6%, 19%, 3,4%;sự khác biệt giữa nhóm nhóm là có ý nghĩa thống kê với p<0.05, OR=2.86, 95%CI=1.203-6.799. Kết luận: Không có mối liên quan giữa đa hình gen SOD2 C47T với nguy cơ vô sinh ở nam giới, nguy cơ vô sinh ở nhóm nam giới mang đa hình gen CAT C262T cao gấp 2.86 lần nam giới bình thường.

Comprehensive analysis of NGS and ARMS-PCR for detecting EGFR mutations based on 4467 cases of NSCLC patients

Background By comparing the detection rate and type of targeted gene mutations in non-small cell lung cancer (NSCLC) between amplification refractory mutation system PCR (ARMS-PCR) and next-generation sequencing (NGS), the characteristics and application advantages of non-small cell lung cancer detection are explained, providing a basis for clinicians to effectively select the corresponding detection methods. Methods and materials The cases of targeted genes for lung cancer were selected from the First Affiliated Hospital of Chongqing Medical University from January 2016 to October 2020. A sample of 4467 cases was selected, and they were diagnosed with NSCLC by Pathological biopsy. Sample sources include surgical resection, bronchoscope biopsy, metastatic biopsy, blood, sputum, cytology of pleural effusion. Among them, 3665 cases were detected by ARMS-PCR technique, and 802 cases were detected by NGS technology. The detection rate and type of ARMS-PCR and NGS techniques for EGFR gene mutations (including exon 18, exon 19, exon 20, exon 21 and so on) in different NSCLC samples were compared, respectively. Results The total mutation rate of EGFR gene detected by ARMS-PCR was 47.6% while 42.4% detected by NGS which indicated that there was a significant difference between the two methods in detecting total mutation of EGFR gene (P < 0.001). In different exons, the EGFR mutation rate detected by two methods is various. The mutation rate of exon 19 by ARMS-PCR detection was evidently higher than that of NGS detection, while the mutation rate of exons 20 and 21 by ARMS-PCR detection were statistically significantly lower than that of NGS detection. Moreover, the multiple mutation rate detected by NGS was 16.3% which was much higher than the 2.7% detected by ARMS-PCR with statistically different. Conclusion It showed that NGS could direct the drug use for the resistant patients. However, some rare loci could be detected by NGS but the importance and directed meaning are still unknown and the number of rare mutations is rare too. Further research on new biomarkers and technique is still needed for early diagnosis, directing drug use and assessing the therapy prognosis.

Evaluating several methods of JAK2 V617F mutation-genotyping to predict the risk of getting polycythemia vera and other myeloproliferative neoplasm diseases

Polycythemia vera, essential thrombocythemia and primary myelofibrosis are members of the Philadelphia negative chronic subgroup of Myeloproliferative neoplasm. Published studies showed that the mutation JAK2 V617F is mostly responsible for the diseases; therefore, an accurate, low-cost and rapid molecular method to identify this mutation is important in screening and early diagnostic of these diseases. Different methods for genotyping of JAK2 V617F have been proposed. In this study, we evaluated the quality and cost-effectiveness of three genotyping methods, i.e., PCR-ARMS, PCR-RFLP, Sanger sequencing, to determine the appropriate genotyping for JAK2 V617F and predicted in silico the effect of this mutation on the structure and function of Janus kinase 2 protein. Results showed that the Sanger sequencing and PCR-RFLP genotyping methods were more accurate than PCR-ARMS. PCR-RFLP was also more rapid and economical than the other methods. In silico studies also demonstrated that the JAK2 V617F mutation had a large effect on the activity of corresponding protein. These results provided the initial data for further studies on genetic screening and prediction of myeloproliferative neoplasm and other related diseases in the Vietnamese population.

The prevalence of DNA base excision repair gene variants among the indigenous Abkhazian population

Актуальность. Загрязнение окружающей среды промышленными отходами, токсическими агентами, опасными излучениями обусловливает возрастание мутационных процессов в биосфере, повреждений ДНК в клетках, рисков онкологических заболеваний. Жизнеспособность организма во многом зависит от наличия эффективных защитных средств против таких неблагоприятных факторов. Невозможность избежать повреждающих ДНК факторов экзогенного и эндогенного характера привела к возникновению более или менее эффективных репарационных систем, суть которых - элиминация первичных повреждений до их воплощения в мутационные события. У человека основным элементом одной из таких систем - эксцизионной репарации оснований ДНК является 8-оксогуанин-ДНК-гликозилаза (OGG1), противостоящая неблагоприятным последствиям оксидативного стресса. Ген OGG1 имеет вариации в кодирующей последовательности, частоты встречаемости которых могут различаться в разных этнических группах, но различаться может и эффективность функционирования продукта трансляции с такого транскрипта. Ser326Cys - яркий тому пример, замена аминокислотного остатка снижает эффективность репарационной функции, и носительство такой мутации, особенно в гомозиготном состоянии, чревато повышенным риском канцерогенеза и некоторыми другими неблагоприятными последствиями для здоровья. Цель. Исследование было направлено на установление частот встречаемости аллелей и генотипов полиморфизма rs1052133 гена OGG1, связанного с эксцизионной репарацией оснований, в популяции абхазов и сопоставление характера распределения с распространенностью в других популяциях Земного шара. Методы. В выборку для исследования абхазской популяции было включено 168 коренных жителей, постоянно проживающих на территории Абхазии. Генотипирование по полиморфизму Ser326Cys в экзоне 7 гена OGG1 (rs1052133) производилось методом ARMS-PCR-RFLP . Результаты. В выборке из абхазской популяции частота генотипа Ser/Ser составила 44,1%, Ser/Cys - 49,4 %, Cys/Cys - 6,5%. Частота аллеля OGG1*С (Ser) оказалась равной 0,688, а OGG1*G (Cys) достигла значения 0,312. Вывод. Частоты аллелей этого полиморфизма в популяции абхазов оказались близки к глобальным среднемировым значениям. Background. Environmental pollutions, toxic agents and dangerous radiation lead to increasing in levels of mutational processes, DNA damages and higher risks of cancer for bioorganisms. The life system viability depends on the effectiveness of the neutralizing the adverse factors. The unavoidance of the DNA damaging factors has led to developing the effective repair systems aimed to eliminate the primary damage. 8-oxoguanine-DNA glycosylase (OGG1) is the major element of the Base Excision Repair (BER) in human. The OGG1 gene has coding sequence variations spread with different frequencies in human populations. Ser326Cys is SNP with known defect in DNA repairing for Cys-allelomorph and an increased risk of cancer in the case. Objective. The study was aimed to estimate the prevalence OGG1 gene variants among the indigenous Abkhazian population and comparison with different ethnic groups worldwide. Methods. The study based on the analysis of 168 samples from Abkhazians. The OGG1 gene Ser326Cys genotyping was performed by the ARMS-PCR-RFLP . Results. The frequency stated for Ser/Ser genotype was 44.1%, Ser/Cys = 49.4 % and Cys/Cys = 6.5% in the Abkhazian population. Frequency of the OGG1 allele*C (Ser) was equal to 0.688, and OGG1*G (Cys) reached the value of 0.312. Conclusion. The frequencies of the rs1052133 alleles in the Abkhazian population were close to the global average values.

SCREENING AND MOLECULAR CHARACTERIZATION OF HAEMOGLOBINOPATHIES USING ARMS (AMPLIFICATION REFRACTORY MUTATION SYSTEM) AND DIRECT DNA SEQUENCING TECHNIQUES AMONG YOUNG IN CENTRAL GUJARAT WESTERN INDIA

Haemoglobinopathies is consider the most common inherited disorders in human and results from genetic mutation in . one or more genes The present study was aimed to characterize the β-thalassemia mutation and haemoglobin variant in youth by ARMS PCR which is an uncomplicated and convenient method for identification of five common mutation from central Gujarat, western India region. This Study included 44 randomly selected haemoglobinopathies carrier student's sample of Anand People's Medicare Society (APMS), Anand for DNA analysis by ARMS PCR from March 2021-April 2021. Identification of five common Indian β thalassemia mutations along with Hb S and HB E were carried out by ARMS PCR method and δβ- thalassemia mutation was characterized by GAP-PCR. The samples which remain uncharacterized were sent to S N gene lab, Surat for DNA sequencing. In our study the most common mutation among five common mutations characterized was IVS-1, nt5 (G→C) in 22 (50%), followed by Codon41/42 (-CTTT) in 5 (11.3%). IVS-1, nt1 (G→T), Codon8/9 (+G) and 619bp del mutation was not identified in any carrier students screened for haemoglobinopathies. Other than these five common mutation Codon -88 (C→T) (2.27%) and Codon 30 (G→A) (2.27%) are also detected. The prevalence of haemoglobinopathies with respect to communities, reflects that SC/ST/OBC are at the highest risk with 50%. Communities like Rajput (22.7%), Patel (18.1%), Brahmin (6.8%) and Muslim (2.2%) are also showing prevalence. The study has included mutation in different communities reflects characterization of mutation of central Gujarat, western India which is significant for rapid and convenient identification of mutation while conducting screening programs and prenatal diagnosis. Rare mutations which are not recognized, need further confirmation for carrier detection followed by prenatal diagnosis.

Comprehensive Analysis of NGS And ARMS-PCR For Detecting EGFR Mutations Based On 4467 Cases of NSCLC Patients

BackgroundBy comparing the detection rate and type of targeted gene mutations in non-small cell lung cancer (NSCLC) between amplification refractory mutation system PCR (ARMS-PCR) and next generation sequencing (NGS), the characteristics and application advantages of non-small cell lung cancer detection are explained, providing a basis for clinicians to effectively select the corresponding detection methods.Methods and materials The cases of targeted genes for lung cancer were selected from the First Affiliated Hospital of Chongqing Medical University from January 2016 to October 2020. A sample of 4467 cases was selected，and they were diagnosed with NSCLC by Pathological biopsy. Sample sources include surgical resection, bronchoscope biopsy, metastatic biopsy, blood, sputum, cytology of pleural effusion. Among them, 3665 cases were detected by ARMS-PCR technique, and 802 cases were detected by NGS technology. The detection rate and type of ARMS-PCR and NGS techniques for EGFR gene mutations (including exon 18, exon 19, exon 20, exon 21 and so on) in different NSCLC samples were compared respectively.ResultsThe total mutation rate of EGFR gene detected by ARMS-PCR was 47.6% while 42.4% detected by NGS which indicated that there was a significant difference between the two methods in detecting total mutation of EGFR gene (P<0.001). In different exons, the EGFR mutation rate detected by two methods is various. The mutation rate of exon 19 by ARMS-PCR detection was evidently higher than that of NGS detection, while the mutation rate of exon 20 and 21 by ARMS-PCR detection were statistically significantly lower than that of NGS detection. Moreover, the multiple mutation rate detected by NGS was 16.3% which was much higher than the 2.7% detected by ARMS-PCR with statistically different. ConclusionsIt showed that NGS could direct the drug use for the resistant patients. However, some rare loci could be detected by NGS but the importance and directed meaning are still unknown and the number of rare mutations is rare too. Further research on new biomarkers and technique is still needed for early diagnosis, directing drug use and assessing the therapy prognosis.