• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.1725-1727
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• 2016

Breast cancer contributes to approximately 23% of the cancer cases identified and 14% of cancer related deaths worldwide. Including a strong association between genetic and environmental factors, breast cancer is a complex and multi factorial disorder. Two high penetration breast cancer susceptibility genes (BRCA1 and BRCA2) have been identified, and germ line mutations in these are thought to account for between 5% and 10% of all breast cancer cases. The human BRCA1 gene, located on 17q, is involved in the regulation of cell proliferation by aiding in DNA repair, transcriptional responses to DNA damage and cell cycle check points. Mutations in this gene enhance cell proliferation and facilitate formation of tumors. Two mutations, the 185 deletion of AG and the 4627 substitution from C to A, are founder mutations in the BRCA1 gene for breast cancer in Asian populations. Allele specific PCR was performed to detect these selected mutations in 120 samples. No mutation of 4627 C to A was detected in the samples and only one of the patients had the 185 del AG mutation in the heterozygous condition. Our collected samples had lower consanguinity and family history indicating the greater involvement of environmental as compared to genetic factors.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4339-4345
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• 2013

Background: The purpose of this study was to evaluate the prevalence of BRCA1 (MIM: 113705) founder mutations in familial breast cancer (BC) patients with high risks in Iran. BRCA1 is among the cancer susceptibility genes best known for high penetrance mutations. BRCA1 genotyping is now used to determine patient counseling, management decisions, and prognosis of this syndrome. Materials and Method: Thirty nine patients with clinical BC and 29 high risk healthy women, related to the patients, participated in the study. DNA from blood samples was extracted and analyzed by PCR and SSCP methods in order to find 185delAG and 5382insC founder mutations. In addition, a 251bp fragment of BRCA1's exon 11 was amplified and analyzed for determination of new mutations. Results: The data indicated the presence of 185delAG and 5382insC founder mutations in both groups studied. Two out of 39 BC patients (5.1%) and one out of 29 relatives (3.4%) were suspected to be carriers of 185delAG mutations. However, we found only one patient (2.6%) to be a carrier of a 5382insC mutation. Also, 2 women (5.1%) of the patient group and 3 n (10.3%) of relatives group were identified as carriers of unclarified mutations in the 251bp fragment of the BRCA1 gene. The carriers of BRCA1 founder mutations have a high lifetime risk of breast cancer. Conclusions: Therefore, these data are useful in counseling of individuals with a significant family history of breast cancer.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7929-7933
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• 2015

Background: The incidence of breast cancer in India is on the rise and is rapidly becoming the number one cancer in females, pushing the cervical cancer to the second position. Most of the predisposition to hereditary breast and ovarian cancer has been attributed to inherited defects in two tumor suppressor genes BRCA1 and BRCA2. Alterations in these genes have been reported in different populations, some of which are population-specific mutations showing founder effects. Two specific mutations in the BRCA1 (185delAG) and BRCA2 (6174delT) genes have been reported to be of high prevalence in different populations. The aim of this study was to estimate the carrier frequency of 185delAG and 6174delT mutations in eastern Indian breast cancer patients. Materials and Methods: We selected 231 histologically confirmed breast cancer patients from our tertiary cancer care center in eastern India. Family history was obtained by interview or a self-reported questionnaire. The presence of the mutation was investigated by allele specific duplex/multiplex-PCR on genomic DNA extracted from peripheral blood. Results: A total of 231 patients (age range: 26-77 years), 130 with a family history and 101 without were screened. The two founder mutations 185delAG in BRCA1 and 6174delT in BRCA2 were not found in any of the subjects. This was confirmed by molecular analysis. Conclusions: Our findings suggest that these BRCA mutations may not have a strong recurrent effect on breast cancer among the eastern Indian population. The contribution of these founder mutations to breast cancer incidence is probably low and could be limited to specific subgroups. This may be particularly useful in establishing further pre-screening strategies.

• Journal of Genetic Medicine
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• 제13권1호
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• pp.20-25
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• 2016

Purpose: Xeroderma pigmentosum (XP) is rare autosomal recessive genetic disorder of DNA repair in which the ability to repair damage caused by ultraviolet light is deficient. We reported the first molecularly confirmed Korean patient of XP by targeted exome sequencing. The prevalence of XP included all subtype and carrier frequency of XP-A the using public data were estimated for the first time in South Korea. Materials and Methods: We described a 4-year-old Korean girl with clinical diagnosis of XP. We performed targeted exome sequencing in the patient for genetic confirmation considering disease genetic heterogeneity and for differential diagnosis. We verified a carrier frequency of c.390-1G>C in XPA gene known as mutational hot spot using Korean Reference Genome Data Base. We estimated the period prevalence of all subtypes of XP based on claims data of the Health Insurance Review and Assessment Service in South Korea. Results: We identified homozygous splicing mutation of XPA (c.390-1G>C) in the patient. The carrier frequency of risk for XPA (c.390-1G>C) was relatively high 1.608 e-03 (allele count 2/1244). The prevalence of XP in South Korea was 0.3 per million people. Conclusion: We expect that c.390-1G>C is hot spot for the mutation of XPA and possible founder variant in South Korea. However, the prevalence in South Korea was extremely low compared with Western countries and Japan.

• 한국동물생명공학회지
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• 제35권4호
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• pp.323-328
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• 2020

Direct injection of genome editing tools such as CRISPR/Cas9 system into developing embryos has been widely used to generate genetically engineered pigs. The approach allows us to produce pigs carrying targeted modifications at high efficiency without having to apply somatic cell nuclear transfer. However, the targeted modifications during embryogenesis often result in mosaicism, which causes issues in phenotyping founder animals and establishing a group of pigs carrying intended modifications. This study was aimed to establish a genomic PCR and sequencing system of a single blastomere in the four-cell embryos to detect potential mosaicism. We performed genomic PCR in four individual blastomeres from four-cell embryos. We successfully amplified target genomic region from single blastomeres of 4-cell stage embryo by PCR. Sanger sequencing of the PCR amplicons obtained from the blastomeres suggested that PCR-based genotyping of single blastomere was a feasible method to determine mutation type generated by genome editing technology such as CRISPR/Cas9 in early stage embryos. In conclusion, we successfully genotyped single blastomeres in a single 4-cell stage embryo to detect potential mosaicism in porcine embryos. Our approach offers a simple platform that can be used to screen the prevalence of mosaicism from designed CRISPR/Cas9 systems.

• 한국수정란이식학회지
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• 제30권4호
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• pp.299-303
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• 2015

KO mice provide an excellent tool to determine roles of specific genes in biomedical filed. Traditionally, knockout mice were generated by homologous recombination in embryonic stem cells. Recently, engineered nucleases, such as zinc finger nuclease, transcription activator-like effector nuclease and clustered regularly interspaced short palindromic repeats (CRISPR), were used to produce knockout mice. This new technology is useful because of high efficiency and ability to generate biallelic mutation in founder mice. Until now, most of knockout mice produced using engineered nucleases were C57BL/6 strain. In the present study we used CRISPR-Cas9 system to generate knockout mice in FVB strain. We designed and synthesized single guide RNA (sgRNA) of CRISPR system for targeting gene, Abtb2. Mouse zygote were obtained from superovulated FVB female mice at 8-10 weeks of age. The sgRNA was injected into pronuclear of the mouse zygote with recombinant Cas9 protein. The microinjected zygotes were cultured for an additional day and only cleaved embryos were selected. The selected embryos were surgically transferred to oviduct of surrogate mother and offsprings were obtained. Genomic DNA were isolated from the offsprings and the target sequence was amplified using PCR. In T7E1 assay, 46.7% among the offsprings were founded as mutants. The PCR products were purified and sequences were analyzed. Most of the mutations were founded as deletion of few sequences at the target site, however, not identical among the each offspring. In conclusion, we found that CRISPR system is very efficient to generate knockout mice in FVB strain.

• Asian Pacific Journal of Cancer Prevention
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• 제16권3호
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• pp.1219-1224
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• 2015

Background: To date several common mutations in BRCA1 and BRCA2 associated with breast cancer have been reported in different populations. However, the common BRCA1 and BRCA2 mutations among breast cancer patients in Iran have not been described in detail. Materials and Methods: To comprehensively assess the frequency and distribution of the most common BRCA1 and BRCA2 mutations in Iranian breast cancer patients, we conducted this meta-analysis on 13 relevant published studies indentified in a literature search on PubMed and SID. Results: A total of 11 BRCA1 and BRCA2 distinct common mutations were identified, reported twice or more in the articles, of which 10 (c.2311T>C, c.3113A>G, c.4308T>C, c.4837A>G, c.2612C>T, c.3119G>A, c.3548A>G, c.5213G>A c.IVS16-92A/G, and c.IVS16-68A/G) mutations were in BRCA1, and 1 (c.4770A>G) was in BRCA2. The mutations were in exon 11, exon 13, intron 16, and exon 20 of BRCA1 and exon 11 of BRCA2. All have been previously reported in different populations. Conclusions: These meta analysis results should be helpful in understanding the possibility of any first true founder mutation of BRCA1/BRCA2 in the Iranian population. In addition, they will be of significance for diagnostic testing, genetic counseling and for epidemiological studies.

• 생명과학회지
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• 제26권4호
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• pp.414-418
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• 2016

본 연구에서는 제주흑돼지와 랜드레이스 품종 사이에서 생산된 F₂ 교배 집단의 경제형질과 isocitrate dehydrogenase 3, beta subunit (IDH3B) 유전자의 유전적 다형성의 상관관계를 시험하였다. IDH3B 유전자의 프로모터 지역에서 304-bp 삽입/결실 돌연변이를 기준으로 전체 1,105 F₂들에 유전자형 분석에 이용하였다. 기초축군과 F₁, F₂에서 세 가지 유전자형(AA, AB, BB)이 모두 발견되었다. 통계적 상관 분석결과에서 도체중(CW), 세 지점(4-5번 흉추 사이, 11-12번 흉추 사이, 13번 흉추-1번 요추 사이)에서 측정한 등지방두께와 도체장(CL)의 수준은 유전자형애 따른 유의적인 차이를 나타내었지만(p<0.05), 육색(MC), 등심단면적(EMA)과 근내지방도(MARB)은 유의적인 차이를 나타내지 않았다(p>0.05). IDH3B 동형접합자 BB를 보유한 F₂ 돼지들은 도체중이 더 무겁고(80.790±0.725 kg), 도체장은 더 짧은(101.875±0.336 cm) 양상을 보였다(p<0.05). 또한, IDH3B 유전자형 BB인 개체들은 IDH3B AA나 AB 유전자형에 비해 4-5번 흉추 사이, 11-12번 흉추 사이에서 측정된 등지방두께도 더 두꺼운 수준을 나타내었다(p<0.05). 이상의 결과들은 IDH3B의 유전적 다양성이 제주흑돼지와 랜드레이스와 관련된 교배육종 체계의 산육능력 향상을 위한 유전적 분자 표지인자로 활용될 수 있음을 나타내었다.

• 생명과학회지
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• 제31권5호
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• pp.453-463
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• 2021

청력 장애(hearing loss)는 임상적 및 유전적으로 상당히 이질적인 질병들의 그룹으로, 일반적으로 증후군 유형(syndromic type)과 비증후군 유형(non-syndromic type)으로 구분된다. 상염색체 열성의 청력 장애 환자가 다른 나라들에 비해 파키스탄에서는 상대적으로 흔하게 관찰되는데, 그 원인으로는 빈번한 근친 결혼의 문화가 일부 관여할 것으로 여겨진다. 본 연구는 상염색체 열성의 청력 장애 환자가 있는 두 파키스탄의 근친 가계를 대상으로 전장 엑솜 서열분석(whole exome sequencing)을 실시하여 유전적 원인을 규명하기 위해 수행되었다. 환자의 유전체 분석 결과, 우리는 언어 습득전 발병(prelingual onset)의 청력 장애 가족으로부터 MYO7A 유전자에서 병원성으로 판단되는 동형접합성 돌연변이인 p.Leu326Gln을 분리하였으며, 조기 발병의 청력 장애와 동시에 근위축(muscular atrophy)을 나타내는 환자 가족에서는 병원성이 확실하지 않는 두 변이(variants of uncertain significance)를 GPR98 유전자(p.Val3094Ile)와 PLA2G6 유전자 (p.Asp56Gly)에서 각각 분리하였다. MYO7A 및 PLA2G6 유전자의 missense 돌연변이는 고도로 보존된 단백질 부위에 위치했으며, 인실리코 분석(in silico analysis)에서도 병원성을 예측하였다. 그러나, GPR98 유전자의 돌연변이는 보존성이 다소 낮은 부위에 위치하였으며, 대부분의 인실리코 분석도 비병원성으로 예측했다. 동형접합성 매핑(homozygosity mapping)을 실시하였을 때, 각 가계에서 분리된 동형접합성 돌연변이의 두 대립유전자가 모두 단일 기원에서 유래한 것으로 예측되었는데, 이것은 근친 결혼에 기인한 것으로 판단된다. 본 연구는 파키스탄의 상염색체 열성 청력 장애 환자들의 정확한 분자진단 및 치료에 도움을 줄 수 있을 것으로 기대된다.