Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 67-year-old woman with pulmonary embolism was suspected to have beta-thalassemia based on microcytosis, hemolysis and a negative red cell stability test. The DNA sequencing analysis of beta-globin gene, however, revealed the deletion of three nucleotides within codon 127-128, leading to substitution of glutamine and alanine residues at 127 and 128 by proline, namely Hb Gunma. This mutant is characterized by the fact that no abnormal hemoglobin is detected in the circulating blood, and is classified as a thalassemic hemoglobinopathy. The present case showed a relatively hemolytic manifestation.
 ...
PMID:Hb Gunma (beta Gunma) with pulmonary embolism. 764 5

Hemoglobin (Hb) M-Saskatoon, a beta variant of methemoglobin, is characterized by mild hemolysis. It is caused by the substitution of a histidine by a tyrosine at the 63rd amino acid residue of the beta-globin chain. Amplification and sequence analysis of genomic beta-globin DNA from an Indonesian boy diagnosed as having the more severe disease thalassemia demonstrated the presence of a C to T transition at nucleotide 473 in one of the two beta-globin genes resulting in a histidine to tyrosine substitution at 63rd residue. This amino acid change matched with that reported in Hb M-Saskatoon. This nucleotide change abolished a recognition site for the restriction endonuclease NlaIII. NlaIII digestion of the corresponding beta-globin DNA amplified from the patient's parents indicated that the mutation was inherited through from his mother. This result shows that the world-wide distribution of Hb M-Saskatoon extends to Indonesia, where it was not previously identified. Possible causes of the unusually severe symptoms observed in the case are discussed.
 ...
PMID:C to T transition at the first nucleotide of codon 63 of the beta-globin gene corresponding to hemoglobin M-Saskatoon in an Indonesian boy. 766

The clinical diversity of thalassemia depends on interaction of diverse genetic defects. We have characterized a severe form of alpha thalassemia caused by coinheritance of a rare alpha-globin gene deletion and a nondeletional defect in a southern Italian family. The proband, a 7-year-old girl, exhibited an abnormal hemoglobin electrophoresis pattern with hemoglobin H and hemoglobin Barts, indicating inheritance of H and hemoglobin Barts, indicating inheritance of a severe form of alpha thalassemia. Southern blot analysis of DNA showed normal as well as aberrant alpha-globin gene fragments indicating heterozygosity for a deletional form of alpha thalassemia in the proband and her mother. The coinheritance of a nondeletional form of alpha thalassemia (alpha alpha T) was suspected because of the severity of the proband's phenotype and the presence of normal alpha-globin gene fragments in the father. Selective polymerase chain reaction of the paternal alpha 1- and alpha 2-globin genes in the proband followed by DNA sequence analysis showed an AATAAA to AATGAA mutation in the polyadenylation signal sequence of the alpha 2-globin gene. Genomic DNA mapping and sequence analysis of a unique polymerase chain reaction product generated across the deletion breakpoint of the maternal allele showed a 5,201-bp deletion extending from 870 nucleotides 5' of the alpha 2-globin gene to nucleotide +519 in the alpha 1-globin gene. This deletion is similar to that previously suggested by blotting studies in a Greek family (Pressley et al, Nucleic Acids Res 8:4889, 1980) and removes the entire alpha 2-globin gene and a portion of the 5' end of the alpha 1-globin gene. Sequence characterization of the resultant aberrant truncated alpha 1-globin gene from the proband showed a 27 nucleotide duplication corresponding to the 3' end of the alpha-globin gene IVS-2 region separated by the insertion of a tetranucleotide (GGTT), suggesting that this deletion is caused by an illegitimate recombination event.
 ...
PMID:Interaction of rare illegitimate recombination event and a poly A addition site mutation resulting in a severe form of alpha thalassemia. 819 72

Microcytosis is a highly prevalent finding during blood examination. This study investigates the causes of microcytosis (defined as mean corpuscular volume (MCV) < 82 fl) in 466 patients referred to our laboratory for suspected hemoglobinopathy. The following data were obtained: Hb, MCV, serum iron, transferrin, ferritin, HbA2, HbF, isoelectric focusing of the Hb, gene mapping of chromosome 16 with Xba I and Bgl II and hybridization with an alpha- and a zeta-probe, inflammatory status. Results show that iron deficiency remains the first cause of microcytosis (35.2% of our patients), even in a selected population such as ours. Deletional alpha-thalassemia, probably the most frequent hemoglobinopathy throughout the world, represents the second most frequent cause of microcytosis (31.1%), followed by beta-thalassemia heterozygous state (18.9%). Of our patients, 1.3% had microcytosis due to the presence of an abnormal hemoglobin (HbC, Hb S/C, HbE). Three cases (0.6%) had other possible causes of microcytosis. Of the remaining 60 cases, 28 had an inflammatory state. Finally, 32 cases (6.9%) remain unexplained; taking into consideration the origin of these cases, their hematological parameters and their family history, we postulate that these cases are at high risk for non-deletional alpha-thalassemia.
 ...
PMID:Investigation of microcytosis: a comprehensive approach. 869 32

Hemoglobinopathies responsible for hemolytic anemias may be divided into two groups. The first one corresponds to thalassemias and the second to the presence of a structurally abnormal hemoglobin (Hb). In thalassemia, the primary biochemical abnormality is a quantitative defect in the biosynthesis of one type of Hb chain. This defect leads to an overall deficit of Hb accumulation in the erythrocyte (hypochromia) together with the presence of an excess of the normally synthesized chains. The unpaired subunits which are less soluble than HbA precipitate, bind to the membrane and ultimately lead to hemolysis. In the second group, the hemolytic anemia is a direct consequence of the physicochemical properties of the structurally abnormal Hb. This molecule may polymerize, precipitate or crystallize within the red blood cell (RBC) leading to membrane alterations and to the destruction of the cell. This chapter will emphasize several examples of structurally abnormal Hbs, such as sickle cell disease and congenital Heinz body hemolytic anemia (CHBHA).
 ...
PMID:Hemolytic anemias due to hemoglobinopathies. 881 15

Twenty subjects--patients with anemia and their close relatives representing 7 families, were tested for thalassemia. Heterozygotic beta-thalassemia was detected in 17 cases. The national composition of this patient population was as follows: 7 Pathans (Afghanistan), 1 family; 2 Armenians (Georgia), mother and son; 2 Tajiks, sibs; 2 patients of mixed Russian-Ukrainian-Polish-Azerbaijan origin, mother and son; 1 Russian-Arab child and his Arab father (Syria); 1 Uzbek woman and 1 Russian child. The mean content of Hb in the blood for patients with heterozygotic beta-thalassemia is 110 +/- 3.8 g/liter, that of HbA2 fraction 4.8 +/- 0.26% and of HbF fraction 2.6 +/- 0.39%. Clinical manifestations of the disease varied, being more grave in children than in adults. In an Armenian family from Batumi thalassemia minor was diagnosed in the mother and son, whereas in the father and other son a periodic disease was revealed. In a family of 7 members from Afghanistan thalassemia minor was found in 4 representing the paternal line, minimal thalassemia was suspected in 3, and a deficiency of glucose-6-phosphate dehydrogenase in red blood cells was revealed in 5: in the mother and 4 children. No increase of methemoglobin level was revealed in either of the examinees.
 ...
PMID:[Beta-thalassemia and glucose-6-phosphate dehydrogenase deficiency]. 904 21

Two major causes of the anemia in beta-thalassemia are a deficiency in hemoglobin (Hb) beta-subunit (and consequently HbA) synthesis and, due to the resulting excess of Hb alpha-subunits, erythroid cell hemolysis. The hemolytic component might be ameliorated by increasing the intracellular proteolysis of the excess alpha-subunits. Isolated 3H-labeled alpha-chains are known to be degraded primarily by the adenosine triphosphate (ATP)- and ubiquitin (Ub)-dependent proteolysis pathway in unfractionated beta-thalassemic hemolysates. Our objective was to increase this degradation by targeted intervention. Ub aldehyde (Ubal), a synthetic inhibitor of isopeptidases (proteases that hydrolyze the bond between the Ub polypeptide and its protein adduct), was added to reaction mixtures containing a hemolysate from the blood cells of one of four beta-thalassemic donors and 3H-alpha-chains or 3H-alpha-globin as a substrate. Optimum enhancement of ATP-dependent degradation occurred at 0.4 to 1.5 micromol/L Ubal and ranged from 29% to 115% for 3H-alpha-chains and 47% to 96% for 3H-alpha-globin among the four hemolysates. We suggest that Ubal stimulates 3H-alpha-subunit proteolysis by inhibition of an isopeptidase(s) that deubiquitinates, or "edits," Ub-3H-alpha-subunit conjugates, intermediates in the degradative pathway. In control studies, similarly low Ubal concentrations did not enhance the degradation of 3H-alpha2beta2 (HbA) tetramers or inhibit the activities of methemoglobin reductase and four selected glycolysis pathway enzymes. These and other results may be the basis for a therapeutic approach to beta-thalassemia.
 ...
PMID:Ubiquitin aldehyde increases adenosine triphosphate-dependent proteolysis of hemoglobin alpha-subunits in beta-thalassemic hemolysates. 924 65

Hematological investigation of an antenatal patient led to the identification of a new beta-thalassemia mutation involving the net insertion of eight nucleotides into exon 2 of the beta-globin gene. As a result of the shift in the protein reading frame, this gene codes for an elongated beta-globin chain (159 amino acids) with an abnormal amino acid sequence beyond residue beta 99. There is no evidence of any abnormal hemoglobin in the circulation. The patient has a mild form of beta-thalassemia intermedia with moderate anemia, evidence of iron overload, severe red cell morphological changes, a significant reticulocytosis, and a marked increase in the proportion of fetal hemoglobin.
 ...
PMID:Mild thalassemia intermedia resulting from a new insertion/frameshift mutation in the beta-globin gene. 941 43

In this report we describe the molecular analysis of 795 chromosomes derived from unrelated Turkish beta-thalassemia and sickle cell anemia carriers identified in hematology clinics in Istanbul, Ankara, Izmir, Adana, and Antalya. The determination of the molecular pathology of 754 beta-thalassemia and 42 abnormal hemoglobin genes and analysis of the frequency distribution in six distinct regions of Turkey was accomplished. The experimental strategy, based on PCR amplification of the beta-globin gene, included dot-blot hybridization with 18 probes specific for the Mediterranean populations, denaturing gradient gel electrophoresis, and genomic sequencing. When the regional results are compared with the overall frequency of mutations in the country, it is observed that the frequencies in the western and southern parts of Turkey are in good accordance with the overall distribution, whereas the northern and eastern parts have a more region/population-specific profile with some rare mutations having a significantly high occurrence in these regions. Further evaluation of the data with respect to region- or population-dependent differences will contribute to a better understanding of the mechanisms leading to the marked genetic heterogeneity in Turkey, but could also be extremely valuable in facilitating rapid identification of mutations in families at risk for different hemoglobinopathies.
 ...
PMID:Molecular and population genetic analyses of beta-thalassemia in Turkey. 949 72

Twelve patients with anemias and their close relatives were examined: 8 adults (3 men and 5 women) and 4 children (3 boys and 1 girl). Six of them were Armenians, 1 woman was Russian, and the rest were of mixed origin: 3 Russian-Azerbaijan-Ukrainian, 1 child Russian-Ukrainian-African, and 1 woman Russian-Ukrainian. Hemoglobinopathies were detected in 10 subjects from 4 families (3 families from Donetsk and 1 from Moscow). Homozygotic beta-thalassemia major (Hb F 98.9%) was diagnosed in a 2-year-old Armenian girl from Donetsk. The girl lags behind in development and suffers from anemia with hepatosplenomegaly and jaundice. Heterozygotic beta-thalassemia minor with increased levels of Hb A2 and Hb F was diagnosed in her parents (Armenians from Azerbaijan). A 15-year-old Russian-Azerbaijan-Ukrainian boy from another family in Donetsk had beta-thalassemia with HbD (94%). The boy suffers from anemia with hepatosplenomegaly, jaundice, and chronic hepatitis. Heterozygotic beta-thalassemia with increased levels of Hb A2 and Hb F was revealed in proband's mother and brother; the father was not examined. alpha-Thalassemia is suspected in a 3-year-old boy from a Russian-Ukrainian-African family in Donetsk; he presented with a very small "fast" abnormal hemoglobin fraction. The boy suffers from anemia with splenomegaly and systolic murmur. Blurred form of thalassemia minor is diagnosed in the mother. The father, an African from Zaire, was not examined. Heterozygotic beta-thalassemia with increased Hb A2 level was revealed in a 20-year-old Armenian boy from Moscow. He presented with manifest splenomegaly, chronic gastritis, and mitral valve prolapse. His mother suffers from thalassemia minor, was anemic during pregnancy, and there are cases of anemia in the family. No hematologic disorders were found in the father. No hemoglobinopathies were detected in a 59-year-old Russian women from the town of Tver with very grave anemia; apparently, her condition was acquired, but not hereditary. Data on patients in the city of Donetsk are of special interest, for there are virtually no reports about hemoglobinopathies in the Ukraine.
 ...
PMID:[Beta-thalassemia and Hb D in patients with anemia]. 957 28


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>