No abstract available.
Exons* ; Point Mutation* ; Steatocystoma Multiplex*

No abstract available.
Introns* ; Point Mutation* ; Protein-Tyrosine Kinases* ; Tyrosine*

Although uncommon, acquired hemophilia A (HA) is associated with a high rate of mortality due to severe bleeding. In spite of many hypotheses regarding the cause of acquired HA, there is as yet no established theory. In this study, we investigated the possibility that mutation(s) in the F8 gene may be correlated with the development of inhibitory autoantibodies. Direct sequencing analysis was performed on all 26 exons of the F8 gene of 2 patients exhibiting acquired HA. Both patients were found to share a common point mutation (c.8899G>A) in the 3'-untranslated region (3'-UTR) of exon 26. This is the first report on the genotyping of F8 in the context of acquired HA.
Autoantibodies ; Exons ; Hemophilia A ; Hemorrhage ; Humans ; Point Mutation

In order to understand the protein functions that are related to disease, it is important to detect the correlation between amino acid mutations and isease. 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 A (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.
Computational Biology ; Crystallization ; Humans ; Hydrophobic and Hydrophilic Interactions ; Isoelectric Point ; Molecular Biology ; Point Mutation ; Protein Engineering ; Proteins

Achondroplasia is abnormal intracartilagenous ossification that's caused by a genetic point mutation. Thoracic myelopathy in achondroplasia that is due to thoracolumbar kyphosis and spinal stenosis is a rare finding. There is no report available on this topic in Korea. We report here a case of achondroplasia with thoracic myelopathy due to thoracolumbar kyphosis and spinal stenosis, and we include a brief review of literature.
Achondroplasia* ; Korea ; Kyphosis* ; Point Mutation ; Spinal Cord Diseases* ; Spinal Stenosis*

Medullary thyroid carcinoma and papillary thyroid carcinoma are different subtypes of thyroid carcinoma. The concomitant occurrence of medullary thyroid carcinoma and papillary thyroid carcinoma as a collision tumor is rare. We describe five cases of medullary and papillary thyroid carcinoma as a collision tumor. Four women and one man underwent thyroidectomy for treatment of thyroid cancer. Collision tumor was then detected by histopathologic finding. Genetic testing, point mutation of the BRAF gene or mutation of the RET gene was performed in three cases. However, only one case had point mutation of the BRAF gene. Exact diagnosis of this uncommon event is important because the strategies for treatment of papillary thyroid carcinoma and medullary thyroid carcinoma are different.
Diagnosis ; Female ; Genetic Testing ; Humans ; Point Mutation ; Thyroid Neoplasms* ; Thyroidectomy

PURPOSE: The aim of this study is to investigate the molecular characteristics of occult hepatitis B virus (HBV) infection in ‘anti-HBc alone’ subjects. MATERIALS AND METHODS: Twenty-four patients with ‘anti-HBc alone’ and 20 control patients diagnosed with HBV were analyzed regarding S and pre-S gene mutations. All specimens were analyzed for HBs Ag, anti-HBc, and anti-HBs. For specimens with an anti-HBc alone, quantitative analysis of HBV DNA, as well as sequencing and mutation analysis of S and pre-S genes, were performed. RESULTS: A total 24 were analyzed for the S gene, and 14 were analyzed for the pre-S gene through sequencing. A total of 20 control patients were analyzed for S and pre-S gene simultaneously. Nineteen point mutations of the major hydrophilic region were found in six of 24 patients. Among them, three mutations, S114T, P127S/T, M133T, were detected in common. Only one mutation was found in five subjects of the control group; this mutation was not found in the occult HBV infection group, however. Pre-S mutations were detected in 10 patients, and mutations of site aa58–aa100 were detected in 9 patients. A mutation on D114E was simultaneously detected. Although five mutations from the control group were found at the same location (aa58–aa100), no mutations of occult HBV infection were detected. CONCLUSION: The prevalence of occult HBV infection is not low among ‘anti-HBc alone’ subjects. Variable mutations in the S gene and pre-S gene were associated with the occurrence of occult HBV infection. Further larger scale studies are required to determine the significance of newly detected mutations.
DNA ; Hepatitis B virus ; Humans ; Point Mutation ; Prevalence

No abstract available.
Animals ; Colon* ; Colonic Neoplasms* ; Oncogenes* ; Point Mutation* ; Rats*

BACKGROUND: Mycobacterium abscessus is the most pathogenic and drug-resistant rapid-growing mycobacterium. Clarithromycin or azithromycin are the only regular oral antimycobacterial agents that have an effect on M. abscessus. We tried to detect the clarithromycin-resistant strains from the clinical isolates of M. abscessus. METHODS: We tried to isolate the clarithromycin-resistant strains from 220 clinical isolates of M. abscessus by performing using reverse hybridization assay (RHA) and the broth microdilution test (BMT). RESULTS: Seven resistant strains (3.2%) from all the tested clinical isolates were detected by BMT. Three of these resistant strains were also detected by RHA and it was confirmed that they had point mutants. CONCLUSION: These results showed that clarithromycin resistance in M. abscessus clinical isolates is related to a point mutation and other unknown mechanisms.
Anti-Bacterial Agents ; Azithromycin ; Chimera ; Clarithromycin ; Mycobacterium ; Point Mutation

BACKGROUND: Antimicrobial resistance is considered as the primary reason for eradication failure of Helicobacter pylori. Resistance to clarithromycin is mostly due to the point mutation in H. pylori 23S rRNA gene. The aims of this study were to determine the primary resistance rate to clarithromycin and metronidazole and to examine the mechanism of clarithromycin resistance in H. pylori isolates. METHODS: Seventy-nine strains were isolated from 73 patients within about five years. The susceptibility of H. pylori isolates to clarithromycin and metronidazole were tested by E-test and broth dilution test. To detect point mutations in the 23S rRNA gene, PCR-RFLP (restriction fragment length polymorphism) was performed. Mutations in clarithromycin-resistant strains also were analyzed by direct sequencing. RESULTS: The resistance rate to clarithromycin (>1 mg/L) and metronidazole (>8 mg/L) were 5.1% and 54.4%, respectively. Annual metronidazole-resistant rates were 43.7% (7/16) in 1996-1997, 61.1% (11/18) in 1998, 55.6% (5/9) in 1999, and 55.6% (20/36) in 2000. Annual clarithromycin- resistant rates were 6.3% (1/16) in 1996-1997, 0% (0/18) in 1998, 11.1% (1/9) in 1999, and 5.6% (2/36) in 2000. Two of 4 clarithromycin-resistant isolates contained the A2144G mutation. One isolate contained A2143G mutation. One isolate possibly contained T2183C mutation. Different strains, isolated separately from antrum and body in 6 patients, showed same susceptibility to clarithromycin. However, different strains in two patients showed different susceptibility to metronidazole. CONCLUSION: No significant increase of resistantce rate to both clarithromycin and metronidazole were found within recent five years. Resistance of H. pylori to clarithromycin was caused by A2144G and A2143G mutation mainly and by T2183C mutation possibly.
Clarithromycin* ; Genes, rRNA ; Helicobacter pylori* ; Helicobacter* ; Humans ; Metronidazole ; Point Mutation