Association of Hb Q-Thailand with homozygous Hb E and heterozygous Hb Constant Spring in pregnancy

Hemoglobin (Hb) Q-Thailand [alpha74(EF3): Asp-->His] is an abnormal Hb found mainly in China and South-east Asian countries. Association of the alpha(Q-Thailand) allele with alpha-thalassemia has important implications in diagnosis. We report the hitherto undescribed conditions of this variant in two unrelated pregnant Thai women. Routine Hb analyses using high-performance liquid chromatography identified abnormal Hb migrating after Hb A(2) in addition to a homozygous Hb E in the proband 1 and to a heterozygous Hb Constant Spring (Hb CS) in the proband 2. Further alpha-globin gene analysis identified that the variant was caused by the GAC to CAC mutation at codon 74 of the alpha1-globin gene corresponding to the Hb Q-Thailand, detected in cis to the 4.2 kb deletional alpha-thalassemia 2 in both cases. Interaction of the alpha(Q-Thailand) with the beta(E) globin chains in the proband 1 leads to a Hb variant, namely the Hb QE. Family study of the proband 1 showed that her non-pregnant sister had the same genotype but her father was a double heterozygote for Hb E and Hb Q-Thailand in whom both Hb Q-Thailand and Hb QE were detected. Genotype-phenotype relationships observed in these families with complex hemoglobinopathies are presented and compared with those of simple homozygote for Hb E, heterozygote for Hb CS and heterozygote for Hb Q-Thailand found in other unrelated subjects. A simple DNA assay based on allele-specific polymerase chain reaction for simultaneous detection of the Hb Q-Thailand mutation and the 4.2 kb deletional alpha-thalassemia 2 determinant was developed and validated.     

Compound heterozygote states for Hb C/Hb Malay and Hb C/Hb E in pregnancy: a molecular and hematological analysis

Hemoglobin (Hb) C (alpha2beta(2)6Glu-Lys) is a variant Hb found mainly in West Africa where individuals carrying both Hb C and Hb S (alpha2beta(2)6Glu-Val) usually have a disease similar to sickle cell disease. The Hb C molecule has reduced solubility leading to crystal formation and hemolytic anemia. We report a hitherto undescribed interaction of Hb C and Hb Malay (alpha2beta(2)19Asn-Ser) in a Thai individual. She was a 24-year-old pregnant woman with moderate anemia who had the following hematologic data; Hb 8.9 g/dl, Hct 30.0%, MCV 81.0 fl, MCH 24.1 pg, MCHC 29.7 g/dl, RDW 17.1% and instead of Hb crystal a marked number of target cell in peripheral blood was observed. Hb analysis revealed 22.5% Hb Malay, 64.6% Hb C and 4.5% Hb A2. Globin gene analyses demonstrated that she carried the betaC mutation (beta6: GAG-AAG) in trans to the betaMalay mutation (beta19: AAC-AGC). Hematologic data of the patient were compared to those of the compound heterozygote for Hb C and Hb E (alpha2beta(2)26Glu-Lys) found in 5 other unrelated Thai pregnant women and 11 pregnant women with Hb C heterozygote with or without co-inheritance of alpha-thalassemia who had much lower Hb C levels and the non-pregnant women with Hb C heterozygote and a compound Hb E/Hb Malay syndrome. Different genotype-phenotype correlations observed in these Thai patients with Hb C disorders are illustrated.     

Thalassemia intermedia is associated with a proatherogenic biochemical phenotype

ObjectiveUnlike beta thalassemia major (β-TM) in which cardiac siderosis represents the leading cause of mortality and morbidity, in beta thalassemia intermedia (β-TI), pulmonary hypertension (PHT) and thrombosis seems to be the major cardiovascular complications. However, the mechanism underlying these complications in β-TI is still unclear. Endothelial dysfunction, the key early event in atherogenesis, is now emerging as an important cardiovascular risk determiner in β-TI patients. Among the factors known to affect endothelial function, iron and cholesterol merit particular consideration in β-TI patients. Therefore, with the aim to extend our knowledge on the mechanisms connecting atherosclerosis to β-TI, in this study, we compared lipid and iron metabolism in serum and in peripheral blood mononuclear cells (PBMCs) from β-TI and β-TM patients and controls.Methods and resultsIn this study the iron status and the lipid profile in serum and in peripheral blood mononuclear cells (PBMCs) of 22 adult β-TI patients were examined, and compared with 70 adult β-TM, and 50 age-matched controls. Despite the great variability, levels of serum iron and transferrin saturation were significantly higher in β-TI compared to both controls and β-TM. By contrast, transferrin and hepcidin levels were lower in β-TI patients. Changes in serum indicators in β-TI patients were associated with altered expressions in PBMCs of hepcidin and IL-1α, involved in some way in the regulation of iron homeostasis. In addition β-TI exhibited a reduction of total and high density lipoprotein cholesterol in serum and of neutral cholesterol ester hydrolase in PBMCs, and an increase of cytoplasmic neutral lipids and mRNA levels of acetyl-coenzymeA:cholesterol acyltransferase.ConclusionsTaken together, these findings provide experimental support for the idea that β-TI patients exhibit a proatherogenic biochemical phenotype which may contribute to enhance cardiovascular risk in these subjects.     

Molecular, hematological and clinical aspects of thalassemia major and thalassemia intermedia associated with Hb E-beta-thalassemia in Northeast Thailand

Hb E-beta-thalassemia is the most common form of beta-thalassemia found in Thailand. The disease exhibits a varied clinical expression ranging from severe transfusion dependence to relatively mild thalassemia intermedia. We evaluated the effects of primary and secondary genetic factors in modulating the hematological and clinical presentation of 148 northeast Thai patients including 103 severe thalassemia major (TM) and 45 thalassemia intermedia (TI). Among 148 cases examined, eleven different mutations including two novel ones; (beta(33/34 (-G)) and beta(IVS2#815 C-T)) were identified in trans to the beta(E) gene in two TM cases. The other 9 known mutations included beta(41/42), beta(17), beta(IVS2#654), beta(-28), beta(71/72), beta(35), beta(IVS1#5), beta(IVS1#1) and beta(41). Except for the beta(-28) mutation which was found only in the TI group, others mutations were identified in both TM and TI. Co-inheritance of alpha-thalassemia as a phenotype modulating factor was not evident in this study, nor was the presence of the -158 (G)gamma-globin Xmn I polymorphism. Further analysis of the polymorphic (TG)n(CG)m repeats within the IVS2 of the two gamma-globin genes revealed no different proportions of the polymorphic patterns among TM and TI groups of patients either. Our data reveals that in the majority of these Hb E-beta-thalassemia patients, it is very hard to predict the clinical phenotype of the patients from the beta-globin mutations and these secondary genetic modifiers.     

Thalassemia heart disease: a comparative evaluation of thalassemia major and thalassemia intermedia

BACKGROUND: Heart disease represents the main determinant of survival in beta-thalassemia, but its particular features in the two clinical forms of the disease, thalassemia major (TM) and thalassemia intermedia (TI), are not completely clarified. METHODS: We compared clinical and echocardiographic global parameters in 131 TM patients who received regular chelation transfusions and were highly compliant with treatment (mean age, 28 +/- 6 years [+/- SD]), and 74 age-matched, TI patients who did not receive chelation transfusions. RESULTS: Congestive heart failure was encountered in five patients with TM (3.8%; age range, 25 to 29 years) and in two patients with TI (2.7%; age range, 37 to 40 years). Systolic left ventricular (LV) dysfunction (ejection fraction < 55% or shortening fraction < 35%) was only encountered in patients with TM (8.4%). Considerable pulmonary hypertension (systolic tricuspid gradient > 35 mm Hg) was only present in TI (23.0%). In the remaining patients without evident heart disease, cardiac dimensions, LV mass, LV shortening and ejection fractions, and cardiac output were significantly higher in patients with TI. LV afterload was higher in patients with TM. LV diastolic early transmitral diastolic peak flow velocity (E)/late transmitral diastolic peak flow velocity (A) ratio was also higher in TM. Systolic and mean pulmonary artery pressures and total pulmonary resistance were higher in both young and old TI patients. CONCLUSION: Regular lifelong transfusion and chelation therapy in TM prevented premature heart disease and pulmonary hypertension, although LV dysfunction still occurred and led to heart failure. The absence of regular therapy in TI, in contrast, preserved systolic LV function but allowed pulmonary hypertension development, which also led to heart failure, starting within the fourth decade of life, a decade later compared to TM.     

Pseudo-Gaucher cells in Hb E disease and thalassemia intermedia

Abstract

Pseudo-Gaucher cells are morphologic curiosities described in a number of conditions. We report their presence in a bone marrow biopsy and a spleen from 2 patients with hemoglobin E disease and thalassemia intermedia, respectively. The pathogenesis of these cells and their multiple known associations are discussed.     

Pseudo-Gaucher cells in Hb E disease and thalassemia intermedia

Pseudo-Gaucher cells are morphologic curiosities described in a number of conditions. We report their presence in a bone marrow biopsy and a spleen from 2 patients with hemoglobin E disease and thalassemia intermedia, respectively. The pathogenesis of these cells and their multiple known associations are discussed.     

Homozygous beta zero-39 mutation with thalassemia intermedia in northern Sardinia: clinical, hematological and molecular analysis

In this study, we investigated the clinical and hematological features and carried out alpha- and beta-globin gene analyses in 11 Sardinian adult beta zero-thalassemia homozygotes from Northern Sardinia who were not transfusion-dependent. Oligonucleotide analysis revealed in nine out of 11 patients the nonsense mutation at codon 39, which was associated either with haplotype II or IX (14/16 and 2/16 chromosomes, respectively). Haplotype II was linked to the A gamma T mutation. The G gamma globin level ranged from 50 to 70%. Four out of nine patients (44%) were heterozygous and 3/9 (33%) homozygous for the rightward deletional type of alpha-thalassemia; two (22%) had the normal alpha-gene complement. Patients who were alpha-thalassemia homozygotes (-alpha/-alpha) showed a more balanced globin chain synthesis ratio. This study confirms that alpha-thalassemia may ameliorate the clinical picture of homozygous beta zero-thalassemia.     

Clinical, hematological, and molecular features in Sicilians with Hb S-beta-thalassemia.

The clinical, hematological, and molecular features of 81 patients with Hb S-beta-thalassemia and relatives from 76 unrelated families are reported. We analyzed the beta-thalassemia mutations and the beta S haplotypes in all patients and detected 6 different beta-thalassemia alleles: codon 39 (C-->T) (39 cases), IVS-I-1 (G-->A) (12 cases), IVS-II-1 (G-->A) (4 cases), IVS-I-6 (T-->C) (6 cases), IVS-I-110 (G-->A) (14 cases), and IVS-II-745 (G-->C) (6 cases). Eighty patients had haplotype #19 or the Benin type and one had haplotype #17 or the Cameroon type. The type of beta-thalassemia allele had the greatest influence on the phenotypic expression; this was observed for patients with Hb S-beta-thalassemia and for simple beta-thalassemia heterozygotes. The mild IVS-I-6 (T-->C) mutation produced borderline abnormal erythrocytic indices and Hb A2 levels in heterozygotes. Overall, there was a milder expression in beta(S) beta(+) patients (only 7.7% presented severe disease) than in those with the beta(S)beta(0) condition (22.6% had the severe form of the disease).     

α‐Thalassemia 2, 3.7 kb deletion and hemoglobin AC heterozygosity in pregnancy: a molecular and hematological analysis

α‐Thalassemia is a synthesis hemoglobinopathy with a worldwide distribution. α‐thalassemia‐2^3.7kb (α‐Thal2^3.7kb) was investigated by PCR and standard hematologic analysis techniques in 106 pregnant women – 53 heterozygous for hemoglobin (Hb) A and C (AC) and 53 homozygous for the normal Hb A (AA) with similar ages and race ancestry. Eleven (21%) of AC women were α‐Thal2^3.7kb heterozygous and 1 (2%) was homozygous, while 12 AA women (23%) were heterozygous. In the AA group, the MCV differed among those with normal α genes and those with α‐Thal2^3.7kb (P = 0.031). Statistical analysis of AC group patients with normal α genes and α‐Thal2^3.7kb carriers showed differences in MCV (P = 0.001); MCH (P = 0.003) and Hb C concentrations (P = 0.011). Analysis of AA and AC group patients with normal α genes showed differences in RBC (P = 0.033), Hb concentration (P = 0.003) and MCHC (P < 0.0001). There were no statistically significant differences for any hematologic parameters between AC and AA group patients with the α‐Thal2^3.7kb genotype. The AC α‐Thal2^3.7kb homozygous women had low hematologic parameters. Serum ferritin levels were normal among the groups studied. These results emphasize the importance of diagnosis and follow‐up of patients with hemoglobinopathy carriers during pregnancy in order to administer adequate therapy and avoid further complications for mothers and newborns.     

Cord blood analysis for rapid prenatal confirmation of Hb Bart's disease using the Sebia Capillary electrophoresis system

Prenatal diagnosis of severe α-thalassemia (α-thal) diseases is usually performed by DNA analysis. To establish a simple and rapid method, we evaluated the reliability of cord blood hemoglobin (Hb) analysis using an automated capillary electrophoresis (CE) system. Our results demonstrated that analysis of fetal Hb using the Sebia CapillaryS 2 is an effective, accurate and simple alternative for prenatal diagnosis of Hb Bart's (γ4) disease.     

Hb Bart's and its significance in the South African Negro.

The haematological indices of cord bloods from 430 South African Negro babies were determined by electronic cell counting and their haemoglobin (Hb) patterns examined by alkaline cellulose acetate electrophoresis. A fast-moving, anodal band, identified as Hb Bart's, was found in 7 (1,6%) of the specimens, this being the lowest incidence of the variant yet found in an indigenous African population. The levels of Hb Bart's ranged from 1.3 to 5.5% of the haemoglobin. These findings were confirmed by alkaline-starch gel electrophoresis and at the same time absence of the slow-moving haemoglobin, Hb Constant Spring was established. Subsequent follow-up of 4 of the infants at 4 months of postnatal life showed that the abnormal component had disappeared. The babies with Hb Bart's had a marked microcytosis and low mean corpuscular haemoglobin levels whilst their parents showed no haematological or electrophoretic signs of alpha-thalassaemia. The significance of these findings is discussed in the light of previously reported studies on various Negro groups.     

alpha-Thalassemia 2, 3.7 kb deletion and hemoglobin AC heterozygosity in pregnancy: a molecular and hematological analysis

alpha-Thalassemia is a synthesis hemoglobinopathy with a worldwide distribution. alpha-thalassemia-23.7kb (alpha-Thal23.7kb) was investigated by PCR and standard hematologic analysis techniques in 106 pregnant women - 53 heterozygous for hemoglobin (Hb) A and C (AC) and 53 homozygous for the normal Hb A (AA) with similar ages and race ancestry. Eleven (21%) of AC women were alpha-Thal23.7kb heterozygous and 1 (2%) was homozygous, while 12 AA women (23%) were heterozygous. In the AA group, the MCV differed among those with normal alpha genes and those with alpha-Thal23.7kb (P = 0.031). Statistical analysis of AC group patients with normal alpha genes and alpha-Thal23.7kb carriers showed differences in MCV (P = 0.001); MCH (P = 0.003) and Hb C concentrations (P = 0.011). Analysis of AA and AC group patients with normal alpha genes showed differences in RBC (P = 0.033), Hb concentration (P = 0.003) and MCHC (P < 0.0001). There were no statistically significant differences for any hematologic parameters between AC and AA group patients with the alpha-Thal23.7kb genotype. The AC alpha-Thal23.7kb homozygous women had low hematologic parameters. Serum ferritin levels were normal among the groups studied. These results emphasize the importance of diagnosis and follow-up of patients with hemoglobinopathy carriers during pregnancy in order to administer adequate therapy and avoid further complications for mothers and newborns.     

Detection of Hb A2 and Hb Constant Spring (HBA2: c.427T>C) by Capillary Electrophoresis in a Patient with Hb H-Hb CS Disease

Abstract

Hb A₂ (α2δ2) is one of the key components looked for in hemoglobinopathies screening programs. Therefore, quantitative and accurate method for Hb A₂ value determination is essential for routine screening. Here, we report a case of Hb A₂ and Hb Constant Spring (Hb CS, HBA2: c.427T>C) with Hb H-Hb CS disease that was not detected by high performance liquid chromatography (HPLC), while Hb A₂ and Hb CS were clearly quantified by capillary electrophoresis (CE).     

Unstable and thalassemic alpha chain hemoglobin variants: a cause of Hb H disease and thalassemia intermedia

We report an update of the alpha-globin gene point mutations resulting in structural modification associated with an alpha-thalassemia (alpha-thal) phenotype. These variants, barely symptomatic in the heterozygous state, are either unstable due to folding defects and/or defects in binding to alpha-hemoglobin stabilizing protein (AHSP). This is predicted to result in precipitation of the unstable alpha chains or Hb variant, a concomitant decrease in the overall quantity of normal alpha-globin in the red cells and a potential degree of anemia and possibly, hemolysis. Genotype/phenotype correlation and potential genetic risk in combination with common or less common alpha-thal defects are discussed.     

Thalassemia intermedia associated with complex interaction of Hb Beijing [alpha16(A14)Lys-->Asn] and Hb E [beta26(B8)Glu-->Lys] with a deletional alpha-thalassemia-1 in a Thai family

A Thai family with a complex thalassemia syndrome caused by alpha- and beta-globin defects is described. The proband was a 14-year-old boy who had chronic hypochromic microcytic anemia. Hemoglobin (Hb) and DNA analyses demonstrated that he carried Hb Beijing [alpha16(A14)Lys-->Asn], Hb E [beta26(B8)Glu-->Lys] and alpha-thalassemia-1 (alpha-thal-1). Interaction of the alphaBeijing with the betaE globin chains in the proband leads to a new Hb variant, namely Hb E Beijing with different characteristics to both Hb E and Hb Beijing. Family studies showed that his father carried Hb Beijing and Hb E, whereas his mother was a simple alpha-thal-1 carrier. The genotype-phenotype relationship observed in this Thai family with complex hemoglobinopathies is presented and a simple DNA assay based on allele specific polymerase chain reaction (ASPCR) for detection of Hb Beijing is described.     

Molecular basis and hematological characterization of Hb H disease in Southeast Asia

We molecularly characterized sixty-seven cases of Hb H disease by the polymerase chain reaction. The strategy depends on amplifying the α-thalassemia-1 (α-thal-1) gene by prlmers flanking the breakpoint and sequence differences of the 3′ end of the α-globin gene and the nonhomologous elements I, II, and III among different types of α-thala-2. In the 67 cases studied, all involved α-thal-1 of the Southeast Asia type (SEA) In combination with deletional or nondeletional α-thal-2. Thirty-two cases were of the deletion form and 35 cases were of the nondeletion form. In 32 cases of the deletion form, 29 cases were rightward deletion (-α^3.7), and three cases were leftward deletion (-α^4.2). We found that all of the nondeletion forms were α-thal-1 of SEA type with Hb CS. After the subtyping of Hb H with -α^3.7, 26 out of 29 were type I deletion and 3 out of 29 were type II deletion. Comparlsons of clinical data of deletion forms and the nondeletion form showed that there were earlier occurrence of anemic symptoms and a larger erythrocyte volume in the nondeletion form group (P < 0.005). © 1994 Wiley-Liss, Inc.