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Related to a-thalassemia: Alpha Thalassemia, Thalassaemia minor


A hereditary form of hemolytic anemia resulting from a defective synthesis of hemoglobin: thalassemia major is the homozygous state accompanied by clinical illness, and thalassemia minor is the heterozygous state and may not have evident clinical manifestations. Also known as Mediterranean anemia.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(also thalassanemia), a familial hemolytic anemia, first detected in 1925 among inhabitants of the Mediterranean region. Thalassemia is caused by disturbances in hemoglobin synthesis.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Positive Correlation between Ferritin and Activated Monocyte in Iron Overloaded Major a-thalassemia Patients.
Vichinsky, "Clinical manifestations of a-thalassemia.," Cold Spring Harbor Perspectives in Medicine, vol.
By analyzing, we found that Hb levels of [beta]-thalassemia patients were significantly lower than [alpha]-thalassemia patients, indicating that [beta]-thalassemia patient's condition is generally more serious than a-thalassemia patients, which may be partly explained by the fact that the clinical efficacy of [alpha]-thalassemia was better than that of [alpha]-thalassemia patients by using Yisui Shengxue Granule, but it needsa large sample of clinical trials by further verification.
The (-(SEA)) a-thalassemia (SEA) deletion ameliorates the clinical phenotype of /[beta](0)/ [beta](+) but not necessarily /3(0)//3(0) thalassemia.
The loss of one (-a/aa), two (-a/-a or --/aa) and three (--/-a) gene are commonly cause a-thalassemia.4 The most common single gene deletions in a-thalassemia are the -a3.7 and the -a4.2, while the double gene deletions in cis, such as the --SEA, --FIL, --THAI alleles are most common in the South-East Asia and the -MED and --a(20.5) double gene deletions occur most frequently in the Mediterranean area.5 In Pakistani population the most common deletion reported is -a3.7 with a frequency of 8.3%, and the rare forms are -a4.2 (0.2%) and -aaaanti3.7 (0.9%).6 Deletion of both a-globin genes on one chromosome are less frequently caused by a point mutation.7 Patients with non-deletional a-thalassemia have a more severe phenotype in contrast with the deletional type.8-10
Most a-thalassemia mutations involve deletions of one (-[alpha]) or both (- -) [alpha]-globin genes, whereas point mutations within the [alpha]-globin genes ([[alpha].sup.T] [alpha] or [alpha] [[alpha].sup.T]) are much less frequent.
In addition, the frequently occurring concomitant a-thalassemia also modifies disease activity.
It occurs at higher percentages in cord blood of newborns with a-thalassemia because of the self-assembly of the accumulating unpaired [gamma] chains.
Nevertheless, the reference range for Hb [A.sub.2] by CIEF needs to be established, particularly the lower limit for normal values, because the diagnosis of minor a-thalassemia is characterized by a low Hb [A.sub.2] value.