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

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

Hemoglobin H disease is often caused by deletion of three of the four alpha-globin genes (genotype: --/-alpha). We studied a Japanese girl who had microcytic hypochromic anemia, a decreased alpha/beta globin synthetic ratio and about 8% Hb H in her fresh hemolysate, by means of restriction endonuclease mapping of the alpha-like gene complex (5'-zeta-phi zeta-phi alpha 2-phi alpha 1-alpha 2-alpha 1-theta-3') with zeta- and alpha-specific probes. It was found that the defect of one chromosome was associated with the removal of about 18 kb of DNA, known as --SEA type alpha-thalassemia-1, including the deletion of the part of phi alpha 2, phi alpha 1, alpha 2, alpha 1, and theta globin genes, while the other one was associated with the removal of 3.7 kb of DNA, known as rightward deletion type alpha-thalassemia-2. The results of a family study demonstrated that the deletion haplotype --SEA was inherited from her father's side and the other -alpha 3.7 from her mother's side.
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PMID:[The molecular basis of HbH disease in a Japanese girl]. 261 58

Both Eco RI and Eco RI x Bam HI restriction endonuclease digests of DNA from black Americans with alpha thalassemia yielded an alpha-specific fragment 4 kb shorter than in normals. In Hb H disease, only the shorter fragment was noted, while in "silent carriers" (alpha-thal 2 trait), both the normal and shorter fragments were detected. One subject with single gene deletions on both homologous chromosomes (alpha-thal 1 phe. A non-deletional form of alpha thalassemia also was discovered.
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PMID:The varied arrangement of the alpha globin genes in alpha thalassemia and Hb H disease in American blacks. 615 3

The deletions in the zeta-alpha globin gene cluster in two infants with the hemoglobin Bart's hydrops fetalis syndrome (homozygous alpha thalassemia 1) have been mapped by restriction endonuclease analysis using a zeta-specific probe. DNA from a Thai infant lacked the psi alpha 1 gene and both alpha genes, but the zeta genes were present. A Greek infant's DNA had also lost the 3' zeta 1 gene. Because zeta globin was synthesized in the infant's cord blood, this indicates that the 5' zeta 2 gene recently identified by Lauer et al. [Lauer, J., Shen, C. J. & Maniatis, T. (1980) Cell, in press] must be functional.
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PMID:Gene deletions in alpha thalassemia prove that the 5' zeta locus is functional. 615 51

Members of a Jewish family of Polish origin were found to have hypochromic, microcytic erythrocytes. By restriction endonuclease analysis of DNA, the propositus, a brother, and an aunt were found to have a single alpha-globin gene on each chromosome 16. Five family members have one chromosome bearing two alpha-genes (5' and 3') with a single alpha-gene on the homologous chromosome. Gene mapping indicated that the chromosome bearing a single alpha-gene arose via an unequal crossover between misaligned 5' and 3' alpha-genes and was introduced into the family from three separate sources. In addition, a Jewish man of Hungarian origin was found to have alpha-thalassemia trait with single alpha-genes on both chromosomes 16 and a survey of 25 Jewish subjects yielded one man of German origin with an alpha-gene deletion. Alpha-thalassemia should be considered in the differential diagnosis of disease in Jewish persons with microcytic, hypochromic erythrocytes.
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PMID:Alpha-thalassemia in Ashkenazi Jews. 630 47

Hemoglobin H (HbH) disease was recently described in three unrelated northern European boys with mental retardation. We have studied a somewhat similar patient, in whom HbH disease was associated with multiple congenital anomalies. Restriction endonuclease analysis of DNA from this proband yielded a pattern consistent with the alpha-/-- genotype commonly associated with the HbH phenotype in Asians. His parents both carry alpha thalassemia, in contrast to the previously described families in which only one of the two parents was a carrier.
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PMID:Hemoglobin H disease and multiple congenital anomalies in a child of northern European origin. 715 27

The different alpha thalassemia genotypes in American and Jamaican black populations have been defined by hematologic and globin-chain synthesis studies, alpha/beta globin messenger RNA ratios and restriction endonuclease mapping of DNA. The results indicate that the common form of alpha thalassemia in these populations is the deletion type of alpha-thalassemia 2 (- alpha/alpha alpha). The homozygous state (- alpha/alpha- alpha) is expressed at birth by the presence of more than 2--3% hemoglobin Bart's; in adult life it has the same phenotype as the heterozygous state for the deletion form of alpha-thalassemia 1 (--/alpha alpha). The heterozygous state is not always associated with detectable amounts of hemoglobin Bart's at birth or with recognizable hematologic changes in adults.
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PMID:alpha thalassemia in black populations. 738 54