Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hereditary hemochromatosis (HHC) represents an autosomal recessive disease in which increased iron absorption causes iron overload and irreversible tissue damage. The recently detected association between two point mutations in the HFE gene on chromosome 6p and HHC has made it possible to screen for the disease before the onset of irreversible tissue damage. Conventional genetic testing is based on restriction fragment-length polymorphisms (RFLP) using two endonuclease recognition sites in codon 63 or 282, respectively. In this study, we have adapted single-strand conformation polymorphism analysis for capillary electrophoresis (SSCP-CE) to detect homozygote or heterozygote point mutations. Two HFE gene fragments spanning codons 63 and 282 were amplified by a duplex PCR using genomic DNA from peripheral blood or from tissue sections of paraffin-embedded liver biopsies as template. Thereby, rapid genotyping of both HFE mutations was achieved with a single PCR, omitting the need of further analysis by restriction digest. Eighty-five patients with liver disease and/or suspected iron overload were genotyped using SSCP-CE, and all results were verified by conventional RFLP analysis. In summary, SSCP-CE proved to be a reliable, cost-effective, sensitive and rapid method for genotyping HFE mutations. This method will further facilitate high-throughput genetic screening using capillary array electrophoretic devices.
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PMID:Rapid genetic screening for hemochromatosis using automated SSCP-based capillary electrophoresis (SSCP-CE). 1037 50

Amplification of the region of the HFE gene that contains the c.845G-->A (C282Y) mutation is usually performed using one amplimer that binds to a sequence in intron 3 and another that binds to a sequence in intron 4. Previously, a mutation that interferes with efficient binding to the intron 4 site has been described. We now find that another common mutation in intron 3, IVS3 -48c-->g, prevents binding of the amplimer to that site. This polymorphism occurs at a gene frequency of 0.128 in the African-American population and at a frequency of only 0.006 in the European population. DNA samples heterozygous for the IVS3 -48c-->g polymorphism and C282Y were undistinguishable from samples homozygous for the C282Y mutation when they were examined by allele-specific oligonucleotide hybridization (ASOH) and showed only a weak normal band when examined by electrophoresis following restriction endonuclease digestion. Although the polymorphism occurs in a DNA sequence almost identical to the intron 3 splice donor site, we found no evidence of alternative splice forms. Moreover, serum iron, transferrin saturation, and serum ferritin levels were normal in subjects heterozygous for the polymorphism. It appears, therefore, that the main importance of this polymorphism is that it may lead to misdiagnosis of heterozygotes for the C282Y mutation as homozygotes. We therefore recommend exonic amplimers that avoid sites that contain polymorphisms and that can be multiplexed for detection of the c.187C-->G (H63D) and c.845G-->A (C282Y) mutations.
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PMID:A common intron 3 mutation (IVS3 -48c-->g) leads to misdiagnosis of the c.845G-->A (C282Y) HFE gene mutation. 1095 Sep 43

Several genes associated with hemochromatosis and primary iron overload have been identified. Mutations in the HFE gene have been detected in 60-100% of hemochromatosis patients of northern, central, and western European descent, although the frequencies of these mutations vary among racial and ethnic groups. Recently, a mutation in the gene encoding transferrin receptor-2 (exon 6, nucleotide 750 C --> G; Y250X) was detected by a PCR-restriction fragment length polymorphism (RFLP) method in Sicilians with hemochromatosis. We describe a modification of the original assay in which the sequence-specific priming PCR assay does not require the use of restriction endonuclease. The modified assay is robust and cost-efficient, and may be more useful for large-scale population studies because it can be performed rapidly on DNA extracted from buccal swabs.
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PMID:A rapid PCR-SSP assay for the hemochromatosis-associated Tyr250Stop mutation in the TFR2 gene. 1155 Oct 99

Our objective was to investigate the frequency of HFE gene mutations and to study linkage disequilibrium (LD) between HLA-Class I alleles and these mutations in the population of Terceira Island, Azores, Portugal. A total of 218 unrelated individuals were investigated. Three HFE mutations--C282Y, H63D, and S65C--were identified by restriction endonuclease digestion of polymerase chain reaction (PCR)-amplified genomic DNA. HLA-Class I alleles were typed by PCR-single-strand polymorphism. Gene frequencies and LD were estimated using Arlequin V 1.1. Six genotypes were found in the population: WT/WT (58.3%), H63D/WT (31.2%), H63D/H63D (2.3%), H63D/C282Y (0.9%), S65C/WT (4.1%), and C282Y/WT (3.2%). No cases of C282Y or S65C homozygosity were identified. HLA haplotype A3-B7 was in LD with C282Y; HLA alleles A29, B44, and HLA haplotype A29-B44 were in LD with S65C mutation. HFE gene frequencies in this population are similar to those in other European populations; HFE S65C mutation was found in LD with the alleles A29, B44, and with A29-B44 HLA haplotype.
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PMID:Linkage disequilibrium between S65C HFE mutation and HLA A29-B44 haplotype in Terceira Island, Azores. 1277 Jul 94

During the last years several genetic markers have appeared which were extensively studied for their clinical consequences and impact. Therefore, we developed 14 new genetic tests using the TaqMan technology. The new test systems detect the alpha1-antitrypsin, ACE, apolipoprotein B-100, apolipoprotein E, factor V Leiden, prothrombin, HFE, MTHFR, COL1A1, VDR and HLA-B27 mutations. These new kits were compared to the established endonuclease restriction digestion and flow cytometry, respectively. The results showed, that the allelic discrimination assays (TaqMan method) were in 100% concordance with the formerly used digestion method. Flow cytometry revealed a lower specificity in contrast to the TaqMan PCR system. Thus, it could be demonstrated that the new TaqMan assays are robust, rapid and automated methods for high throughput applications which avoid time consuming (and therefore expensive) and difficult post-PCR steps.
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PMID:A highly reproducible and economically competitive SNP analysis of several well characterized human mutations. 1520 39