Seven unrelated patients with hemoglobin (Hb) H disease and 27 individuals with alpha-chain structural alterations were studied to identify the alpha-globin gene mutations present in the population of Southeast Brazil.
Seven unrelated patients with hemoglobin (Hb) H disease and 27 individuals with alpha-chain structural alterations were studied to identify the alpha-globin gene mutations present in the population of Southeast Brazil.
Haemoglobin H (Hb H) disease is the severest form of alpha-thalassaemia compatible with post-natal life and occurs when alpha-thalassaemia mutations interact to reduce alpha-globin synthesis to levels approximately equivalent to the output of a single alpha-globin gene.
Haemoglobin H (Hb H) disease is the severest form of alpha-thalassaemia compatible with post-natal life and occurs when alpha-thalassaemia mutations interact to reduce alpha-globin synthesis to levels approximately equivalent to the output of a single alpha-globin gene.
The results confirm the importance of the alpha 2 alpha 1-mRNA for the synthesis of alpha chains in alpha-thalassemia-2 homozygotes (-alpha/-alpha) and in patients with Hb H disease due to the deletion of three alpha-globin genes (-alpha/--).
The results confirm the importance of the alpha 2 alpha 1-mRNA for the synthesis of alpha chains in alpha-thalassemia-2 homozygotes (-alpha/-alpha) and in patients with Hb H disease due to the deletion of three alpha-globin genes (-alpha/--).
The study depended on (a) most of the Hb H disease in Taiwan having an alpha-thalassemia-1 of the Southeast Asia type (--SEA) in one allele and (b) the differences of X box of alpha-globin gene cluster in the other allele.
The study depended on (a) most of the Hb H disease in Taiwan having an alpha-thalassemia-1 of the Southeast Asia type (--SEA) in one allele and (b) the differences of X box of alpha-globin gene cluster in the other allele.
We utilized the PCR method to amplify the alpha-thalassemia-1 breakpoint area of the Southeast Asia type and several regions of the alpha-globin gene cluster to diagnose rightward deletion (-alpha 3.7), leftward deletion (-alpha 4.2) or nondeletion forms of the Hb H disease.
We utilized the PCR method to amplify the alpha-thalassemia-1 breakpoint area of the Southeast Asia type and several regions of the alpha-globin gene cluster to diagnose rightward deletion (-alpha 3.7), leftward deletion (-alpha 4.2) or nondeletion forms of the Hb H disease.
In this population sample we did not find either heterozygous carriers of alpha 0 thalassemia (deletion of both alpha genes in "cis") or individuals showing hemolytic anemia due to inactivation of three alpha-globin genes (Hb H disease).
In this population sample we did not find either heterozygous carriers of alpha 0 thalassemia (deletion of both alpha genes in "cis") or individuals showing hemolytic anemia due to inactivation of three alpha-globin genes (Hb H disease).
Analysis of DNA from members of a Melanesian family from Papua New Guinea with haemoglobin (Hb) H disease revealed that all four alpha globin genes are intact in affected subjects.
Analysis of DNA from members of a Melanesian family from Papua New Guinea with haemoglobin (Hb) H disease revealed that all four alpha globin genes are intact in affected subjects.
The only infant with the deletion of 3 alpha-globin structural genes had 25% Hb Bart's associated with a moderate microcytic anemia at birth and developed the clinical picture of Hb H disease.
The only infant with the deletion of 3 alpha-globin structural genes had 25% Hb Bart's associated with a moderate microcytic anemia at birth and developed the clinical picture of Hb H disease.
The chromosomes showing loss of one alpha-globin gene in alpha-thalassemia-2 and Hb H disease were characterized by the so-called rightward deletion form exhibiting loss of a 3.7 kb DNA fragment in the alpha-gene cluster.
The chromosomes showing loss of one alpha-globin gene in alpha-thalassemia-2 and Hb H disease were characterized by the so-called rightward deletion form exhibiting loss of a 3.7 kb DNA fragment in the alpha-gene cluster.
These results suggest that in those Hb H disease patients with the non-deletion [(alpha alpha)th] determinant, two alpha globin genes produce fewer alpha globin chains than a single alpha globin locus.
These results suggest that in those Hb H disease patients with the non-deletion [(alpha alpha)th] determinant, two alpha globin genes produce fewer alpha globin chains than a single alpha globin locus.
In a previous study, molecular cloning of the alpha-globin genes from a patient with nondeletion Hb-H disease (genotype--/alpha alpha) showed that a single nucleotide mutation (CTG to CCG) in one of the genes resulted in a leucine to proline substitution.