Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Significant DNA polymorphisms have been reported in the beta-globin gene cluster of epsilon-G gamma-A gamma-psi beta-delta-beta-gene region, in normal (Hb AA) individuals and in patients with sickle cell anaemia (SCA). Investigations of the extent of the DNA polymorphisms in the beta A- and beta S-globin gene cluster using Hind III, Hinc II, Ava II, Xmn I, and Hpa I, revealed several associations with mild SCA. The correlation of the presence (+) or absence (-) of the restriction endonuclease site to clinical severity in patients homozygous for beta S-gene showed that the mild form of SCA was associated mainly (> 90%) with the Xmn I polymorphic site 5' to G gamma, and to a lesser extent with Hinc II polymorphic site 5' to epsilon and in the psi beta-gene, with Hind III polymorphic site in G gamma and Hpa I polymorphic site 3' to the beta-globin gene, while in the severe form of SCA these polymorphic sites were absent in most patients. The polymorphism in the beta-globin gene cluster was significantly related to the expression of the beta S-gene and clinical severity of SCA.
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PMID:DNA polymorphism in the beta-globin gene cluster in Saudi Arabs: relation to severity of sickle cell anaemia. 128

A 680 base-pair sequence of the human beta-haemoglobin gene was reproducibly amplified in individual unfertilised human oocytes and in first polar bodies isolated from them. Specificity and sensitivity of amplification were achieved by two sequential reactions with two sets of primers, amplifying first a 725 base-pair sequence and secondly a 680 base-pair sequence from within the first amplified fragment. A restriction enzyme digest of the DNA amplified from a single oocyte with the endonuclease Dde I confirmed the identity of the amplified beta-haemoglobin fragment; this technique provides a diagnostic test for the genetic defect responsible for sickle cell anaemia. Analysis of the DNA from the first polar body may enable detection of such defects in unfertilised eggs from carrier women. Selection of eggs without the defect for fertilisation may therefore obviate the need for diagnostic procedures on embryos.
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PMID:Amplification of a beta-haemoglobin sequence in individual human oocytes and polar bodies. 169 29

The foetal haemoglobin (HbF) levels and the haplotypes of beta s chromosomes in sickle cell anaemia patients in Nigeria were evaluated. The mean HbF level was 5.9 +/- 3.8% with a range of 0.9-16.7%. 80% of the patients had HbF values below 8% and 94% had HbF levels below 10%. No significant difference in haematological parameters was seen between those with less than 2% HbF and those with greater than 8% HbF. The presence (+) or absence (-) of eight restriction endonuclease enzyme sites within the beta s globin gene cluster (haplotype) on chromosome 11 were mapped. The common haplotype (- - - - + + - +) in 97% of the chromosomes examined closely correlates with the low levels of foetal haemoglobin generally observed in sickle cell patients in the same population.
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PMID:Relationship of foetal haemoglobin levels and beta s haplotypes in homozygous sickle cell disease. 169 9

Restriction endonuclease analysis was used to detect alpha-gene deletions and to determine the haplotypes in the DNA of the beta S-gene-cluster [Benin, Central African Republic (CAR), and Senegal] in 221 patients with sickle cell anemia (SS). The clinical expression of SS was modified by the beta S-gene-cluster polymorphisms and the alpha-gene status (alpha-thalassemia-2). The overall risk of soft tissue organ failure caused by the obliterative sickle vasculopathy (including stroke, renal failure, chronic lung disease with cor pulmonale, leg ulcers, and young adult death) was increased threefold in those with a CAR haplotype and was decreased in those with a Senegalese chromosome (p = 0.003). In the presence of a Senegalese haplotype, the patient's health is better, and with the CAR haplotype it is always worse. With the Benin, it is intermediate. Acute recurrent clinical events including hospitalized sickle cell crisis, bone infarction, and infection are decreased in frequency in those with a Senegalese haplotype. The risk of most acute events including acute chest syndrome is equivalent in those with Benin or CAR haplotypes. In the United States, alpha-thalassemia-2 is co-inherited randomly among the beta S-gene-cluster haplotypes. Acute events occurring during childhood are minimally effected by this co-inheritance. The risk of soft tissue organ failure is decreased. After the age of 20 years, painful episodes of the lumbar dorsal area are increased in patients who had alpha-thalassemia-2 in association with degenerative bone disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Beta S-gene-cluster haplotypes in sickle cell anemia: clinical implications. 170 Jun 39

The haploid nucleus of a human cell contains 3 X 10(9) base pairs. Organized in linear duplex, this DNA would stretch out to a length of some 90 cm. Thus, organization of chromosomes has been a major subject for pioneer cytogenetists. Long lasting controversies on the strandedness of chromosomes, together with newly developed banding techniques, led us to molecular cytogenetics. Next, the discovery of reverse transcriptase, restriction endonucleases, and other recombinant DNA methods have enabled us to isolate and characterize genes from any organism and to determine the DNA sequences and any encoded protein sequences. These new technologies have already helped us to understand many inherited diseases at a molecular level. In sickle cell anemia, thalassemia and in other mendelian disorders we can know their molecular defects by examining the DNA from peripheral leukocytes, without the need for complex biochemical assays or biopsies. Southern blot analysis using restriction endonuclease and a probe is a basic tool for molecular diagnosis. cDNA or DNA fragments are used as probes. Recently, synthesized oligonucleotide probes are available, if the DNA sequence of a gene is determined. In addition, restriction fragment length polymorphisms (RFLPs), play a very important role in the molecular diagnosis. Linkage analysis using RFLPs linked to the gene locus of a certain disease also permits the detection of the patients and carriers within families with genetic diseases of unknown cause. Starting with the genetic map and physical map, genes for cystic fibrosis and Duchenne muscular dystrophy have recently been isolated and cloned.
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PMID:[Recent advances in human molecular genetics]. 197 24

A specific DNA probe containing part of the structural B-globulin gene was used to confirm the diagnosis of sickle cell anemia in a caucasian woman. The patient's genomic DNA was digested with the restriction endonuclease Dde I, fractioned by agarose electrophoresis and Southern blotting. Molecular hybridization was performed with the DNA probe prepared by chemical labelling with photobiotin. The beta 8/beta 8 genotype rendered only 1 fragment of length 376 bp. Upon digestion with Dde I, the DNA of an individual with the normal genotype containing the enzyme recognition sequence at the site of sickle cell mutation, resulted in 2 fragments of 201 and 175 bp. The pedigree of the patient's caucasian family was studied by Hb electrophoresis. Four out of 7 brothers carried the sickle cell trait.
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PMID:[Use of a specific DNA probe to confirm sickle cell anemia in a caucasian woman]. 213 13

Many patients with sickle cell anaemia (SCA) are known to synthesize increased amounts of foetal haemoglobin (Hb F). In some situations, the levels attained are so high that the course of the disease is ameliorated since Hb F does not participate in the polymerization process characteristic of the sickling phenomenon. It has also been reported that the simultaneous inheritance of an alpha-thalassaemia gene reduces the severity of SCA. We have examined the levels of Hb F in relation to the erythrocyte indices and the coinheritance of the deletion type alpha-thalassaemia in SCA patients in Nigeria. The concentration of Hb F in peripheral blood was measured by the alkali denaturation technique of Betke et al. [15], whilst erythrocyte indices were determined on a Coulter S plus II counter. Alpha-thalassaemia was detected by the restriction endonuclease analysis of DNA obtained from peripheral white blood cells (WBC) and nucleated red cells using alpha-globin gene-specific probes. The mean Hb F level in 130 SCA subjects was 5.9 +/- 3.8% (range 0.9-16%). Males had significantly lower levels than females. Hb concentration, haematocrit, and Hb A2 did not differ in subjects with Hb F levels lower than 2% (Group I) when compared with those whose Hb F levels were higher than 8% (Group II). The mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) were lower in Group I. Globin analysis in 30 of these subjects showed that 20 had four, eight had three, and two had two alpha-globin genes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Foetal haemoglobin levels in sickle cell anaemia in Nigerians. 247 39

Restriction endonuclease analysis of DNA was undertaken in blood samples from individuals who were normal (110), had sickle cell trait (44) and homozygous sickle cell disease (6) from the tribal populations of Bihar, Madhya Pradesh, Gujarat and southern Rajasthan. DNA was prepared from all the blood samples and processed for restriction enzyme digestion, agarose electrophoresis, prehybridization, Nick-translation hybridization and autoradiography. A polymorphic HpaI restriction endonuclease recognition site on the 3' side of the beta-globin gene was used to analyse to determine the beta-globin gene mutant S. It was found that mutation has resulted within the normal 7.6 Kb HpaI fragment among the tribal populations studied. On comparing the results with those from Middle East and East Africa it appears that the sickle gene mutation in India, Saudi Arabia and Kenya arose separately from that in West Africa.
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PMID:Restriction endonuclease analysis of DNA in sickle cell lesions among tribals of Bihar, Madhya Pradesh, Gujarat & Rajasthan. 257 21

Patients with sickle cell anemia vary in the hematologic and clinical features of their disease, in part because of variability in the presence of linked and unlinked genes that modify the expression of the disease. The hemoglobin S gene is strongly linked to three different haplotypes of polymorphic endonuclease-restriction sites of the beta-like gene cluster (genes in the vicinity of the beta-globin gene)--one prevalent in Atlantic West Africa, another in central West Africa, and yet another in Bantu-speaking Africa (equatorial, East, and southern Africa). We have studied the differences in the hematologic characteristics of patients with sickle cell anemia from the first two geographical areas. We find that the Senegalese (Atlantic West Africa) patients have higher levels of hemoglobin F, a preponderance of G gamma chains in hemoglobin F, a lower proportion of very dense red cells, and a lower percentage of irreversibly sickled cells than those from Benin (central West Africa). We interpret these data to mean that the gamma-chain composition and the hemoglobin F level are haplotype linked and that the decrease in the percentage of dense cells and irreversibly sickled cells is secondary to the elevation in the hemoglobin F level. Patients with sickle cell anemia in the New World probably correspond to various combinations of these types, in addition to the still hematologically undefined haplotype associated with sickle cell anemia in the Bantu-speaking areas of Africa.
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PMID:Hematologically and genetically distinct forms of sickle cell anemia in Africa. The Senegal type and the Benin type. 257 36

The purpose of the present study was to investigate the effect of alpha-thalassemia on the prevalence of avascular necrosis in 52 adult patients with sickle cell anemia. alpha-Globin genotypes were determined by restriction endonuclease mapping of genomic DNA extracted from peripheral blood leukocytes. Radiographs of humeral and femoral heads were interpreted by two radiologists who were not aware of the clinical picture and the genotype of the patients in the study. We present data showing that there is a significant positive correlation between alpha-gene deletion and the prevalence and extent of avascular necrosis in our patient population.
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PMID:The prevalence of avascular necrosis in sickle cell anemia: correlation with alpha-thalassemia. 263 66


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