Heterocellular hereditary persistence of fetal hemoglobin (HPFH). Molecular mechanisms of abnormal gamma-gene expression in association with beta thalassemia and linkage relationship with the beta-globin gene cluster.
The beta-globin gene clusters of three unrelated Thai families with a nondeletional type of hereditary persistence of fetal haemoglobin (HPFH) were studied using polymerase chain reaction-related techniques.
Hereditary persistence of fetal hemoglobin (HPFH) is a benign condition caused by the failure of normal switching from the fetal to the adult beta-globin gene, resulting in continuous production of fetal hemoglobin beyond the perinatal period.
Hereditary persistence of foetal haemoglobin (HPFH) and (δβ)(0) -thalassaemia are conditions caused by large deletions that involve δ- and β-globin genes in the β-globin cluster, and they are characterized by increased haemoglobin (HbF) levels in adults.
The breakpoint of a large deletion causing hereditary persistence of fetal hemoglobin occurs within an erythroid DNA domain remote from the beta-globin gene cluster.
The analysis of a number of cases of beta-globin thalassemia and hereditary persistence of fetal hemoglobin (HPFH) due to large deletions in the beta-globin locus has led to the identification of several DNA elements that have been implicated in the switch from human fetal gamma- to adult beta-globin gene expression.
We report a new type of deletion of the beta globin gene cluster in the Italian population that confers a phenotype of hereditary persistence of fetal hemoglobin (HPFH) to the carriers.
A considerable number of deletions of variable size and position that involve the beta-globin gene complex on chromosome 11 are associated with the clinical entities of hereditary persistence of fetal hemoglobin (HPFH) and delta beta thalassemia.
A novel 30 kb deletion of the beta-globin gene cluster associated with the phenotype of hereditary persistence of fetal hemoglobin (HPFH) is described in two unrelated individuals of Vietnamese background.
The most common forms of hereditary persistence of fetal hemoglobin synthesis (HPFH) and delta beta zero-thalassemia result from simple deletions of the beta-globin gene cluster or from point mutations in the gamma-globin gene promoters.
Interaction of two different disorders in the beta-globin gene cluster associated with an increased hemoglobin F production: a novel deletion type of (G) gamma + ((A) gamma delta beta)(0)-thalassemia and a delta(0)-hereditary persistence of fetal hemoglobin determinant.
Southern blot analysis using probes 3' to the beta-globin gene showed that the deletion extends in the 3' direction further than any other deletions associated with delta beta-thalassemia and hereditary persistence of fetal hemoglobin (HPFH) heretofore reported.
The genetic mechanisms underlying the continued expression of the gamma-globin genes during the adult stage in deletional hereditary persistence of fetal hemoglobin (HPFH) and deltabeta-thalassemias are not completely understood.
Individuals heterozygous for the Greek (A gamma) variant of hereditary persistence of fetal haemoglobin (HPFH) synthesize Hb F whose gamma-globin chains are predominantly of the A gamma type.
G gamma A gamma (beta+) hereditary persistence of fetal hemoglobin: the G gamma -158 C-->T mutation in cis to the -175 T-->C mutation of the A gamma-globin gene results in increased G gamma-globin synthesis.
However, certain point mutations in the gamma-globin gene promoter are capable of maintaining expression of this gene during adult erythropoiesis, a condition called non-deletion hereditary persistence of fetal hemoglobin (HPFH).
Single base substitutions have been identified in the promoter regions of A gamma-globin genes from individuals with certain types of nondeletion A gamma hereditary persistence of fetal hemoglobin (HPFH).
In order to address these problems, we investigated an enhancer element identified from individuals with deletional hereditary persistence of fetal hemoglobin 2 (HPFH2), a genetic condition characterized by elevated levels of gamma-globin in adults.