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

The rarity of hemoglobin (Hb) H disease in combination with sickle trait may be due in part to the absence of actual Hb H in individuals who, nonetheless, have inherited the deletion of three alpha-globin genes. We describe here a boy with persistent microcytic, hypochromic anemia despite adequate iron stores, who exhibited splenomegaly with a normal reticulocyte count and only rare inclusions in circulating erythrocytes. Starch gel electrophoresis and isoelectric focusing at age 5 yr showed 21% Hb S, persistent Hb Bart's, but no Hb H. Recticulocyte alpha/non-alpha globin chain synthesis ratio was 0.58 at age 5. The mother (Asian) had laboratory evidence of alpha-thalassemia trait and the father (Black) had sickle trait. The nature of alpha-thalassemia in this patient was investigated both by liquid hybridization and by the Southern method of gene mapping, in which DNA is digested with restriction endonucleases and the DNA fragments that contained the alpha-globin structural gene identified by hybridization with complementary DNA. The patient had only one alpha-globin structural gene, located in a DNA fragment shorter than that found in normal or alpha-thalassemia trait individuals, but similar to that present in other patients with Hb H disease. Morphologic studies of bone marrow by light and electron microscopy revealed erythroid hyperplasia with inclusions in polychromatic and orthochromatic erythroblasts, suggesting early precipitation of an unstable hemoglobin. The lack of demonstrable Hb H may be the result of both diminished amounts of beta(A) available for Hb H formation (since one beta-globin gene is beta(S)) and the greater affinity of alpha-chains for beta(A) than beta(S)-globin chains leading to the formation of relatively more Hb A than Hb S. The presence of a beta(S) gene may thus modify the usual clinical expression of Hb H disease.
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PMID:Modification of hemoglobin H disease by sickle trait. 47 66

A 6-year-old child of northern European ancestry was found to have microcytic, hypochromic anemia with an elevated level of hemoglobin A2 and an unbalanced pattern of globin chain synthesis characteristic of beta-thalassemia trait. Hematologic and globin synthesis studies of both parents yielded entirely normal results. Identification of the mother and father as the biological parents was established with a high order of reliability by determination of erythrocyte, serum, and HLA genetic markers. These findings suggest that the picture of beta-thalassemia observed in this child represents a new mutation.
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PMID:beta-Thalassemia arising as a new mutation in an American child. 67 20

The clinical hematologic change in 2 groups of progeny from mice carrying radiation-induced strain SEC alpha-chain deficiencies was found to be similar to the hematologic alterations in persons with alpha-thalassemia. The heterozygous deletion or inactivation of the alpha-chain gene in mice caused an anemia similar to alpha-thalassemina minor in persons. The alpha-chain deficiency in mice created an erythrocytosis, reticulocytosis, and microcytic, hypochromic anemia comparable with the changes in human alpha-thalassemia minor resulting from deletion of the alpha-chain gene. These mouse mutants are the only known animal models of human thalassemia. A comparison of hematologic values obtained from progeny possessing an alpha-chain gene deficiency and from progeny possessing a beta-chain duplication suggested that the deficiency of alpha-chain synthesis, rather than a simple imbalance between the amounts of alpha- and beta-chains produced, was primarily responsible for the altered hematologic characteristics in these alpha-thalassemic mice.
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PMID:Radiation-induced alpha-thalassemia in mice. 87 56

A previously unrecognized hypochromic anemia associated with marked normoblastemia during the newborn period is reported. One male and two female siblings and a first cousin had a hypochromic anemia and marked normoblastemia (300 to 900 normoblast index per 100 white blood cells) at birth. Globin chain synthesis studies on peripheral blood of the proband at birth indicated the presence of alpha-thalassemia trait with possible reduced gamma chain synthesis. Studies of globin chain synthesis on the father, two older affected siblings of the proband, and the proband at 1.5 years of age revealed alpha-thalassemia trait. The data suggest this complex alpha-thalassemia-like condition as a new syndrome associated with marked neonatal normoblastemia.
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PMID:Complex alpha-thalassemia-like syndrome: a cause of neonatal normoblastemia. 95 73

A 26-year-old Chinese-Malaysian female patient with beta-thalassemia is presented. The main hematological values found in this patient were as follows: 1) normocytic hypochromic anemia (RBC 444 x 10(4)/microliters, Hb 11.8 g/dl) with marked anisopoikilocytosis, 2) erythroid hyperplasia, and 3) increased HbF (HbA 41.4%, HbA2 2.9%, HbF 48.9%). DNA obtained from peripheral leukocytes was analyzed using dot blot hybridization of the polymerase chain reaction (PCR)-amplified DNA with allele-specific oligonucleotide probes. A C----T substitution at position 654 of the second intervening sequence (IVS-2) was detected in her beta-globin clone.
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PMID:A case of beta-thalassemia with a C----T substitution at position 654 of the second intervening sequence of the beta-globin gene. 160 Feb 78

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

Hypochromic anaemia is very common among the island populations of Vanuatu in the South-West Pacific. Results of a large-scale survey show that, unexpectedly, this form of anaemia is seldom due to iron deficiency or coexistent parasitic disease. Rather, it results from a previously unsuspected high incidence of alpha-thalassaemia which has been identified only by application of DNA analysis to the populations studied. These findings suggest that hypochromic anaemia in tropical or subtropical populations should not necessarily be attributed to iron deficiency; detailed studies of iron status should be carried out before major dietary changes or fortification of food with iron are implemented.
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PMID:Relative roles of genetic factors, dietary deficiency, and infection in anaemia in Vanuatu, South-West Pacific. 286 13

Alpha thalassemia is rarely diagnosed in Australian families of British or Northern European ancestry. In 1972, a third generation Australian was shown to have alpha thalassemia. In the absence of known Mediterranean or South East Asian ancestry it was reported as being the first example of alpha thalassemia in an Australian family. Further study of the proposita in 1985 using DNA mapping of the alpha globin gene complex, shows a distinctive molecular defect identical to the British type of alpha thalassemia. The latter is clearly different from the commonly encountered Mediterranean and South East Asian alpha zero haplotypes. Recognition that alpha zero thalassemia occurs in Australians is important since it may produce a microcytic hypochromic anemia. Its inheritance together with other forms of alpha thalassemia may lead to severe Hb H disease or Hb Bart's hydrops fetalis.
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PMID:Alpha thalassemia British type (alpha alpha/--Brit) in an Australian family. 302 Apr 89

Hb Knossos (beta 27 (B9) Ala----Ser) is a recently discovered hemoglobin variant endowed with beta-thalassemic properties (1,2) We present the first homozygous cases. The propositus, a 19-year-old man is originally from northeast Algeria, but is unrelated to other Algerians who have hemoglobin Knossos. He has a beta(+)-thalassemia intermedia syndrome, including microcytic, hypochromic anemia, enlargement of the spleen, and an increase in the number of reticulocytes. The reduction of beta-chain synthesis is pronounced (alpha/non alpha:2.76). Whole cells containing Hb Knossos have a dramatically low oxygen affinity (P50:38 mm Hg). The propositus also has homozygous delta(0)-thalassemia. The chromosome carrying these mutations is characterized by the DNA haplotype I.
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PMID:Homozygous hemoglobin Knossos (alpha 2 beta 227(B9) Ala----Ser): a new variety of beta (+)-thalassemia intermedia associated with delta (0)-thalassemia. 395 38

Thirteen Canadians with a mild hypochromic anemia were found to have beta thalassemia trait. The families of these individuals had resided in Canada for two to five generations and, where known, had not emigrated from areas with a high incidence for the thalassemia gene. A Negro family with abnormal erythrocyte morphology was suspected to be carrying the thalassemia gene although the hemoglobin A(2) concentration was normal and abnormal minor components were not detected. Thalassemia trait has been detected in practically every ethnic group, and its sporadic occurrence among Canadians without Mediterranean ancestry can be expected.
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PMID:Thalassemia in Canadians. 601 42


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