• BMB Reports
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• v.29 no.5
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• pp.442-447
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• 1996

Mutations in codon 12, 13 and 61 of one of the three ras genes, H-ras, K-ras and N-ras, convert these genes into active oncogenes. The presence of H-ras gene mutations have important prognostic implications in various cancers. In this study, the H-ras gene mutations were investigated by two-step PCRRFLP in patients with bladder and stomach cancer. For the control experiments, T24 and SK2 cell lines were used. In a total of 36 bladder cancer patient cases, five (13.9%) mutations were found by this method. Of these, point 12 mutations were two (5.6%) cases and point 61 mutations were three (8.3%) cases. On the other hand, H-ras mutation was not found in 29 cases of stomach cancer. The results of the mutated H-ras gene confirmed by direct sequencing analysis were correlated well with PCR analysis. From the sensitivity test, the H-ras mutation was found to have about 0.2% of mutated DNA mingled in normal DNA. In conclusion, the H-ras mutation has a higher clinical Significance in bladder cancer than stomach cancer. Moreover the two-step PCR-RFLP method is sensitive, rapid and relatively simple for clinical work in detecting H-ras point mutations.

• Journal of Yeungnam Medical Science
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• v.16 no.1
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• pp.114-118
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• 1999

Leber's hereditary optic neuropathy(LHON) is an optic nerve disease that causes blindness and is associated with maternally inherited mitochondrial DNA(mt DNA) mutations. The most common mitochondrial DNA mutation among LHON patients is a point mutation at the nucleotide 11778 in the subunit 4 of complex I. In one 45-year old male LHON patient with bilateral optic neuropathy. we investigated the presence of a point mutation of mitochondrial DNA and identified a single guanine to adenine transition mutation in the mitochondrial DNA at nucleotide point 11778.

• BMB Reports
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• v.46 no.5
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• pp.270-275
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• 2013

It is essential to analyze rare mutations in many fields of biomedical research. However, the detection of rare mutations is usually failed due to the interference of predominant wild-type DNA surrounded. Herein we describe a sensitive and facile method of detecting rare point mutation on the basis of allele-specific amplification in emulsion PCR. The identification and selective amplification of rare mutation are accomplished in one-pot reaction. The allele-specific primers coupled on magnetic beads allow the exclusive amplification and enrichment of the mutant amplicons. The productive beads bearing mutant amplicons are subsequently stained with the fluorescent dyes. Thus, the rare point mutations with a percentage as low as 0.1%, can be detected by fluorescent analysis. The relative percentages of mutation among different samples can be roughly accessed by counting the fraction of fluorescent positive beads through flow cytometry.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.195-198
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• 2002

To identify mutations in exons 5 to 8 of the p53 tumor suppressor gene, we have analysed in 12 spontaneous canine tumors. In a malignant mast cell tumor, a 1 base pair alteration AGT $\longrightarrow$AGC (silent point mutation, serine) in codon 249 in exon 8 was detected. And the mammary gland adenocarcinoma was found to have a mis-sense point mutation (CCT $\longrightarrow$ TCT) in codon 285 in exon 8.

• Journal of Gastric Cancer
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• v.3 no.3
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• pp.145-150
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• 2003

Purpose: The p53 tumor suppressor gene is believed to play a pivotal role in preventing the uncontrolled cellular growth characteristic of cancer. Mutation of the p53 gene represent one of the most common genetic alterations in human cancers, and the acquisition of such defects is strongly associated with tumor progression and metastasis. The aim of this study was to evaluate the relation between p53 immunoreactivity and the mutation of p53 gene in gastric adenocarcinoma obtained by laser capture microscope. Materials and Methods: Formalin fixed paraffin embedded tissue specimens were obtained from 20 patients who underwent surgery for gastric cancer. According to UICC TNM system, 3 of the cases were Ia, 2 cases II, 4 cases IIIa, 5 cases IIIb, and 6 cases IV. Results: Immunohistochemical staining revealed eight cases as negative (less than $10\%$), twelve cases as postive (more than $10\%$). The locations of mutations were as follows; 7 cases had point mutation at exon 4, and 3 cases point mutation at exon 8. There was no mutation at exon 5, 6, 7 and 9. The mutation was observed in 1 case out of 8 p53 oncoprotein negative cases, and 7 cases out of 12 p53 positive cases. The mutation was more common in p53 positive cases (P<0.05), However, there was no significant correlation between p53 mutation observed by DNA sequencing after laser capture microdissection and expression of p53 oncoprotein. Conclusion: These result suggest that he expression of p53 oncoprotein not to be related to the mutation of p53 gene at exons 4 through 9 in gastric cancer.

• Development and Reproduction
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• v.4 no.1
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• pp.61-66
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• 2000

This study was investigated to analyze the inactivating point mutation and expression level of follicle-stimulating hormone(FSH) receptor mRNA. In first experiment, we analyzed the point mutation. Peripheral blood was collected from each patient. To screen individuals for the C566T mutation, PCR was performed for exon 7 of the FSH receptor gene in 10 patients. No inactivating point mutation of FSH receptor gene was identified in women with premature ovarian failure. To analyze the expression level of FSH receptor, mRNA expressions were examined by RT-PCR method using specific primers for the FSH receptor. The amount of FSH receptor mRNA expressed in POF patients was lower than that in the control group. But it was not significantly different. These finding suggests that lower expression of FSH receptor in premature ovarian failure patients might be the cause of the low response to the gonadotropin during the hyperstimulation in IVF-ET cycles.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.3
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• pp.157-162
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• 2003

Our earlier studies found a significant correlation between the activities of ranitidine N-oxidation catalyzed by hepatic flavin-containing monooxygenase (FMO) and the presence of mutations in exon 4 (E158K) and exon 7 (E308G) of the FMO3 gene in Korean volunteers. However, caffeine N-1 demethylation (which is also partially catalyzed by FMO) was not significantly correlated with these FMO3 mutations. In this study, we examined another common mutation (V257M) in exon 6 of FMO3 gene. The V257M variant, which is caused by a point mutation (G769A), was commonly observed (13.21% allele frequency) in our subjects (n=159). This point mutation causes a substitution of $Val^{257}$ to $Met^{257}$, with transformation of the secondary structure. The presence of this mutant allele correlated significantly with a reduction in caffeine N-1-demethylating activity, but was not correlated with the activity of N-oxidation of ranitidine. In a family study, the low FMO activity observed in a person heterozygous for a nonsense mutation in exon 4 (G148X) and heterozygous for missense mutation in exon 6 (V257M) of FMO3 was attributed to the mutations. Our results suggest that various point mutations in the coding regions of FMO3 may influence FMO3 activity according to the probe substrates of varying chemical structure that correlate with each mutation on the FMO3 gene.

• Genomics & Informatics
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• v.6 no.3
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• pp.142-146
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• 2008

In order to understand the protein functions that are related to disease, it is important to detect the correlation between amino acid mutations and disease. Many mutation studies about disease-related proteins have been carried out through molecular biology techniques, such as vector design, protein engineering, and protein crystallization. However, experimental protein mutation studies are time-consuming, be it in vivo or in vitro. We therefore performed a bioinformatic analysis of known disease-related mutations and their protein structure changes in order to analyze the correlation between mutation and disease. For this study, we selected 111 diseases that were related to 175 proteins from the PDB database and 710 mutations that were found in the protein structures. The mutations were acquired from the Human Gene Mutation Database (HGMD). We selected point mutations, excluding only insertions or deletions, for detecting structural changes. To detect a structural change by mutation, we analyzed not only the structural properties (distance of pocket and mutation, pocket size, surface size, and stability), but also the physico-chemical properties (weight, instability, isoelectric point (IEP), and GRAVY score) for the 710 mutations. We detected that the distance between the pocket and disease-related mutation lay within $20\;{\AA}$ (98.5%, 700 proteins). We found that there was no significant correlation between structural stability and disease-causing mutations or between hydrophobicity changes and critical mutations. For large-scale mutational analysis of disease-causing mutations, our bioinformatics approach, using 710 structural mutations, called "Structural Mutatomics," can help researchers to detect disease-specific mutations and to understand the biological functions of disease-related proteins.

• Bulletin of the Korean Chemical Society
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• v.27 no.9
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• pp.1346-1352
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• 2006

We describe an effective method of microchip electrophoresis (ME) based on single strand conformation poly-morphism (SSCP) analysis to rapidly detect the point mutation, Leu72Met, in a human obesity gene. The 207-bp dsDNA in the Leu72Met region, an estimate of the child obesity DNA mutant, was amplified by polymerase chain reaction (PCR) and submitted to a conventional glass microchip analysis with a sieving matrix of 1.75% poly(vinylpyrrolidone) (Mr 1 300 000), 1.0% poly(ethyleneoxide) (Mr 600 000) and 5.0% w/w glycerol. When combined with base stacking (BS) with hydroxide ions, the SSCP-ME provided rapid analysis as well as sensitive detection. The detection sensitivity was effectively enhanced in the OH- concentration range of 0.01-0.025 M NaOH. The sensitivity and speed of this ME-based SSCP methodology for the rapid detection of Leu72Met point mutations makes this an attractive method for diagnosing childhood obesity in a clinical diagnostic laboratory.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.3
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• pp.281-286
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• 1998

Premature ovarian failure is a condition causing amenorrhea, hypoestrogenism, and elevated gonadotropins in women younger than 40 years. Many causes of premature ovarian failure were reported, including genetic abnormalities, enzymatic defects, defects in gonadotropin secretion or action, autoimmune disorders, physical and idiopathic causes. Recently, Finnish group reported a point mutation in the follicle stimulating hormone (FSH) receptor gene in premature ovarian failure patients. But it was reported that the group from United States could not find any mutation in FSH receptor gene. So we analysed C566T point mutation of FSH receptor gene using restriction fragment length polymorphism (RFLP) and compared the result between premature ovarian failure patient with idiopathic and known causes. But we did not find 556C${\rightarrow}$T mutation in the FSH receptor gene in both groups. These findings suggest that the missense mutation in the human FSH receptor gene reported in Finnish women with premature ovarian failure is uncommon in Korean women with premature ovarian failure.