HbE, the result of a G to A mutation in codon 26 of the HBB (β-globin) gene, activates a cryptic 5' splice site in codon 25 leading to a reduction of correctly spliced β(E) -globin (HBB:c.79G>A) mRNA and consequently β(+) -thalassaemia.
Ten patients with thalassemia intermedia with variable severity and apparent simple heterozygosis for beta0 39 C>T nonsense mutation were submitted to clinical, hematologic and molecular studies.
Although this mutation would be expected to produce an unstable haemoglobin and hence a haemolytic anaemia, simple heterozygotes for the alpha 29Leu-->Pro mutation have the phenotype of alpha-thalassaemia trait.
These signs correspond to her marked hypochromic, microcytic anemia with erythroid hyperplasia of the bone marrow. beta-Globin genotyping shows here to be compound heterozygous for the codon 39 C-->T beta zero-nonsense mutation and for the T-->C beta(+)-mutation at position 6 of the splice consensus at the exon 1/intron 1 junction (CD39 C-->T/IVS1-6 T-->C). alpha-Globin gene mapping demonstrates the presence of a 3.7-kb alpha (+)-thalassemia deletion on one allele (-alpha 3.7/alpha alpha).
These signs correspond to her marked hypochromic, microcytic anemia with erythroid hyperplasia of the bone marrow. beta-Globin genotyping shows here to be compound heterozygous for the codon 39 C-->T beta zero-nonsense mutation and for the T-->C beta(+)-mutation at position 6 of the splice consensus at the exon 1/intron 1 junction (CD39 C-->T/IVS1-6 T-->C). alpha-Globin gene mapping demonstrates the presence of a 3.7-kb alpha (+)-thalassemia deletion on one allele (-alpha 3.7/alpha alpha).
These signs correspond to her marked hypochromic, microcytic anemia with erythroid hyperplasia of the bone marrow. beta-Globin genotyping shows here to be compound heterozygous for the codon 39 C-->T beta zero-nonsense mutation and for the T-->C beta(+)-mutation at position 6 of the splice consensus at the exon 1/intron 1 junction (CD39 C-->T/IVS1-6 T-->C). alpha-Globin gene mapping demonstrates the presence of a 3.7-kb alpha (+)-thalassemia deletion on one allele (-alpha 3.7/alpha alpha).
A new silent hemoglobin variant, Hb Ozieri (alpha 71(E20)Ala-->Val), was observed in five apparently unrelated newborn babies during a screening for hemoglobinopathies on the island of Sardinia.
Hybridization patterns of DNA restriction enzyme fragments showed that in HbQ-alpha 2 74 Asp replaced by His beta 2-alpha-thalassemia one chromosome has both alpha-globin genes deleted and the other chromosome, which carries the alpha-mutant gene, has one alpha-globin gene deleted.
Hybridization patterns of DNA restriction enzyme fragments showed that in HbQ-alpha 2 74 Asp replaced by His beta 2-alpha-thalassemia one chromosome has both alpha-globin genes deleted and the other chromosome, which carries the alpha-mutant gene, has one alpha-globin gene deleted.