A Repository of Deletional HPFH and δβ-Thalassemia Conditions

Phenotypic heterogeneity of asian Indian inversion deletions gγ(aγδβ)0 breakpoint a and breakpoint B

Asian Indian inversion deletion Gγ (Aγδβ)0-thalassemia is a rare entities characterized by high HbF. Due to interaction with various genetic factors, patients with Gγ (Aγδβ)0-thalassemia showed clinical variability. Here we are presenting the phenotypic expression of Gγ(Aγδβ)0 thalassemia under influence of various co-inherited factors. Patient with α-globin gene deletion had mild phenotype than the patient with β-globin mutations. Patient with alpha gene deletion were presenting clinical character like thalassemia intermedia while Gγ (Aγδβ)0-thalassemia patients with co- presence of beta thalssemia mutation clinically behaved like thalassemia major.

Compound heterozygote state for GgammaAgamma(deltabeta) degrees -thalassemia and hereditary persistence of fetal hemoglobin

We report a hitherto undescribed interaction of a deletional (deltabeta) degrees -thalassemia and a deletional hereditary persistence of fetal hemoglobin (HPFH) in an adult Thai individual. He was a 40-year-old Thai male who had the following hematologic data: Hb 13.9 g/dL, Hct 43.8%, MCV 78.0 fL, MCH 24.7 pg, MCHC 31.6 g/dL, and RDW 17.1%. Hemoglobin analysis revealed 97% Hb F with Ggamma-globin chain predominant. Globin gene analyses demonstrated that he carried the GgammaAgamma(deltabeta) degrees -thalassemia deletion in trans to the HPFH-6. Hematologic data of the patient were compared to those of the heterozygotes for these high-Hb F determinants found in his parents and an unrelated Thai patient with a compound HPFH-6/deletion-inversion Ggamma(Agammadeltabeta) degrees -thalassemia previously described.

Molecular and hematological characterization of HPFH-6/Indian deletion-inversion Ggamma(Agammadeltabeta)0-thalassemia and Ggamma(Agammadeltabeta)0-thalassemia/HbE in Thai patients

The hereditary persistence of fetal hemoglobin (HPFH)-6 is sporadically found in Thailand whereas the deletion-inversion type (G)gamma((A)gamma delta beta)(0)-thalassemia is described among Indians. We report a hitherto un-described case in which these two defects co-segregate. He was a 3-year-old Thai boy who had a feature of thalassemia intermedia phenotype with the following hematologic data; Hb 8.8 g/dL, Hct 29.2%, MCV 66.9 fL, MCH 20 pg, and MCHC 30.1 g/dL. Hemoglobin analysis revealed 100% Hb F with only (G)gamma-globin chain. Globin gene analyses demonstrated that he carried the HPFH-6 deletion in trans to the Indian deletion-inversion (G)gamma((A)gamma delta beta)(0)-thalassemia. Hematologic data of the patient was compared to those of the HPFH-6 heterozygote found in his father, to (G)gamma((A)gamma delta beta)(0)-thalassemia heterozygotes detected in his mother and sister, and to that of an unrelated Thai patient who was a compound heterozygote for the deletion-inversion (G)gamma((A)gamma delta beta)(0)-thalassemia and HbE.

Molecular characterization of (deltabeta)(0)/beta(0)-thalassemia and (deltabeta)(0)-thalassemia/hemoglobin E in Thai patients

Two cases of the Thai thalassemia patients with compound heterozygosities for (deltabeta)(0)/beta(0)-thalassemia and (deltabeta)(0)-thalassemia/hemoglobin E have been reported. The first case was a 8-yr-old boy who had the following hematologic data: Hb 6.5 g/dL, Hct 20.5%, MCV 70.4 fL, MCH 22.3 pg and MCHC 31.7 g/dL. Hemoglobin analysis revealed 1.9% hemoglobin A2 and 91.7% hemoglobin F. The second case, with Hb 13.9 g/dL, Hct 41.5%, MCV 69.5 fL, MCH 22.5 pg and MCHC 32.2 g/dL, was a 16-yr-old male who had 46.1% hemoglobin E and 49.8% hemoglobin F. Globin gene analyses showed that both probands carried the same deletional type (deltabeta)(0)-thalassemia trans to the 4 bp deletions in codons 41/42 beta(0)-thalassemia and to the betaE-globin gene, respectively. Polymerase chain reaction and DNA sequence analyses demonstrated that the 5' breakpoint of the (deltabeta)(0)-thalassemia deletion was located in the second intron of the delta-globin gene and that the 3' breakpoint lay within a cluster of LI repetitive sequences at 4.7 kb 3' to the beta-globin gene.

Delta beta-thalassemia in an African-American: identification of the deletion endpoints and PCR-based diagnosis

We describe an African-American child with beta-thalassemia intermedia. Molecular studies revealed that the proband is a compound heterozygote for the -29 (A-->G) beta (+)-thalassemia mutation and an extensive deletion involving the delta- and beta-globin genes. The proband's mother is a simple carrier of the deletion and exhibits the phenotype of delta beta-thalassemia rather than hereditary persistence of fetal hemoglobin. The deletion spans 11,767 bp, with the 5' deletion endpoint located 2,455 bp upstream of the delta-globin gene mRNA Cap site and the 3' endpoint located 441 bp downstream of the termination codon of the beta-globin gene. Based on this information, we have developed a polymerase chain reaction strategy for the rapid detection of this delta beta-thalassemia deletion.