1/136. Antenatal diagnosis of Bart's hydrops fetalis [correction of homozygous alpha thalassemia]. A case report.OBJECTIVE: diagnosis of the Bart's hydrops fetalis [corrected]. METHOD: Bart's hydrops fetalis [corrected] was discovered by chance in the fetus of a female Chinese patient. Major intrauterine growth retardation, oligohydramnios, an immobile fetus, and cardiomegaly were the principal echographic signs. cordocentesis showed fetal anemia, and electrophoresis of fetal hemoglobin revealed the presence of Bart's hemoglobin. RESULT: As there is no known effective treatment, termination of pregnancy was proposed to the patient. CONCLUSIONS: Bart's hydrops fetallis [corrected] is a lethal condition. Early echographic signs (cardiothoracic index >0.50, placental thickening) can be screened during weeks 17-18 or even during weeks 13-14 of gestation. These signs would permit a reduction of invasive examinations in couples at risk.- - - - - - - - - - ranking = 1keywords = h (Clic here for more details about this article) |
2/136. Homozygous alpha-thalassaemia and hypospadias--common aetiology or incidental association? Long-term survival of Hb Bart's hydrops syndrome leads to new aspects for counselling of alpha-thalassaemic traits.Fetuses with homozygous alpha-thalassaemia develop Hb Bart's hydrops fetalis syndrome, which usually leads either to abortion or fetal/neonatal death. We report diagnosis, intrauterine transfusion therapy, neonatal intensive care management and long-term follow-up of a Vietnamese infant who survived Hb Bart's hydrops fetalis syndrome. During the first 2 years the child had normal development. In addition, the patient exhibited penoscrotal hypospadias. Despite a thorough endocrinological work-up the aetiology of genital ambiguity could not be elucidated. A review of the literature showed an association of homozygous alpha-thalassaemia and hypospadias in all surviving male children, suggesting a common aetiology for both entities. CONCLUSION: On the basis of our findings, we speculate that an unknown gene on chromosome 16 responsible for genital formation is altered in homozygous alpha-thalassaemia.- - - - - - - - - - ranking = 1.4634146341463keywords = h (Clic here for more details about this article) |
3/136. alpha-Thalassaemia due to a single codon deletion in the alpha1-globin gene. Computational structural analysis of the new alpha-chain variant. Mutations in brief no. 132. Online.A new unstable alpha-globin chain associated with alpha-thalassemia phenotype has been found in a Spanish patient. Molecular analysis of the alpha-globin gene complex using PCR and non-radioactive single-strand conformation analysis, allowed to identify a new mutation in the second exon of the alpha-globin gene. Direct sequencing of the abnormal fragment revealed a 3 bp deletion, which led to the loss of a single codon corresponding to a Lys (K) residue at position 60 or 61 DK60 or DK61. Theoretical structural analysis, performed by computational methods, indicated that the loss of an amino acid residue at this position disturbed the contact region between the B and E-helices, affecting the overall stability of the molecule. Therefore, the DK60 and DK61 results in a structurally abnormal alpha-globin chain, not previously described, named Hb Clinic, which leads to the alpha-thalassemia phenotype in the heterozygote patient. No abnormal hemoglobin was detected by standard electrophoretic procedures, suggesting that this alpha-globin chain variant is so unstable that it may be catabolized immediately after its synthesis. This mutation was confirmed by PCR using an allele specific primer.- - - - - - - - - - ranking = 796346.11814712keywords = alpha-thalassemia, h (Clic here for more details about this article) |
4/136. Intrathoracic extramedullary haematopoiesis complicated by massive haemothorax in alpha-thalassaemia.Intrathoracic extramedullary haematopoiesis (EMH) is a rare entity that is usually asymptomatic. A 44 year old man with alpha-thalassaemia is described who developed dyspnoea and massive left sided haemothorax. The haemoglobin disorder was established by Hgb H staining and haemoglobin electrophoretic studies. The dna analysis revealed it to be a case of double heterozygous terminal codon mutation with the genotype alphaalphaCS/alphaalphaT. Computed tomographic scanning and magnetic resonance imaging of the thorax showed multiple paravertebral masses which were found by thoracoscopic biopsy to be extramedullary haematopoiesis. Although no additional sclerosing pleurodesis or low dose radiation therapy was given, the lung expanded well and there has been no recurrence of haemothorax to date.- - - - - - - - - - ranking = 311.08130632687keywords = haemoglobin, h (Clic here for more details about this article) |
5/136. Homozygous alpha-thalassemia associated with hypospadias in three survivors.We report three cases of homozygous alpha-thalassemia (alphaTH) who survived beyond the neonatal period, all with hypospadias. A review of literature identified two additional male cases of homozygous alphaTH who survived, and both had hypospadias. The simultaneous occurrence of the two conditions seems beyond coincidence and may be causally related. Possible pathogenesis for the association may be 1) homozygous alphaTH-induced in utero and/or edema secondary to hydrops fetalis, both leading to the failure of proper fusion of the urogenital folds, or 2) defect of another gene located at a chromosome 16p13.3 region. Thus, parents who request intrauterine therapy for a male fetus with homozygous alphaTH should be informed about this association and its prognosis.- - - - - - - - - - ranking = 1990862.0026849keywords = alpha-thalassemia, h (Clic here for more details about this article) |
6/136. Laboratory recognition of a rare hemoglobinopathy: hemoglobins SS and SG(philadelphia) associated with alpha-thalassemia-2.This article describes the laboratory investigation of an unusual hemoglobinopathy involving hemoglobin (Hb) S, HbSG(philadelphia), and alpha-thalassemia-2 in a patient whose phenotype was HbSC by alkaline electrophoresis. Findings of a mean corpuscular volume of 62 fL and microcytes on the blood smear were inconsistent with HbSC disease. The patient's clinical course over several years had been mildly symptomatic. Testing in our hospital laboratory using isoelectric focusing and cation-exchange high-performance liquid chromatography to separate hemoglobins showed an unknown variant. Additional studies, including globin chain electrophoresis, reverse-phase high-performance liquid chromatography, and polymerase chain reaction-based dna analysis were performed at reference laboratories, which reported the following findings: HbG(philadelphia) associated with alpha-thalassemia-2, HbS and HbG(philadelphia), and the alpha-globin deletions defining the -alpha3.7/-alpha3.7 genotype. The hemoglobin molecular defects, alpha-thalassemia-2, and the pattern of inheritance are discussed.- - - - - - - - - - ranking = 2787206.9988808keywords = alpha-thalassemia, h (Clic here for more details about this article) |
7/136. Hb Aghia Sophia [alpha62(E11)Val-->0 (alpha1)], an "in-frame" deletion causing alpha-thalassemia.In this report we describe a case of Hb H disease due to the interaction of the --(MED 1) deletion with a new alpha( )-thalassemia determinant. The molecular analysis of the proband's genomic dna was carried out by polymerase chain reaction amplification and sequencing of both alpha genes of the alpha( )-thalassemia chromosome and revealed a deletion of codon 62 of the alpha1 gene. This dna triplet codes for a valine residue at the E11 alpha helix, which is located in the interior of the heme pocket. Substitutions of valine E11 with other amino acid residues in the alpha as well as beta polypeptide chains lead, in the heterozygous carrier, either to Hb M disease or to congenital non-spherocytic hemolytic anemia. We assume that the deletion of valine at alpha62(E11) disrupts the conformation of the alpha chain to such an extent that the mutated subunit is rapidly removed by proteolysis. The final result is an alpha-thalassemia phenotype rather than an unstable hemoglobin syndrome. This conclusion is supported by the apparent absence of an abnormal alpha chain in the peripheral blood of the patient.- - - - - - - - - - ranking = 1990862.710002keywords = alpha-thalassemia, h (Clic here for more details about this article) |
8/136. Interaction of an alpha( )-thalassemia deletion with either a highly unstable alpha-globin variant (alpha2, codon 59, GGC-->GAC) or a nondeletional alpha-thalassemia mutation (AATAAA-->AATAAG): comparison of phenotypes illustrating "dominant" alpha-thalassemia.Thalassemia syndromes and unstable hemoglobins traditionally represent two phenotypically separate disorders of hemoglobin synthesis. Highly unstable hemoglobin variants, however, often have phenotypic characteristics associated with both ineffective erythropoiesis (thalassemias) and peripheral hemolysis (unstable hemoglobins). Many highly unstable beta chain variants cause a dominant thalassemia-like phenotype, in which simple heterozygotes for such mutations have a clinical expression similar to thalassemia intermedia. The phenotypic expression of highly unstable alpha-globin variants is usually less severe, due mainly to a gene dosage effect, and they are often only characterized on interaction with other alpha-thalassemia mutations, whence they are classified as nondeletional alpha-thalassemia determinants. This study reports the clinical and hematological findings in five cases with rare alpha-thalassemia genotypes: a single patient with the thalassemic alpha2-globin gene codon 59 Gly-->Asp hemoglobin variant in trans to an alpha( )-thalassemia deletion, and four compound heterozygotes for the nondeletional alpha-thalassemia polyadenylation mutation (alpha2 gene AATAAA-->AATAAG or alpha(T-Saudi)alpha/-alpha) and an alpha( )-thalassemia deletion. Evaluation of the clinical and hematological features in these two analogous genotypes clearly demonstrates the more severe clinical expression associated with the alpha-thalassemic unstable hemoglobin variant. In addition, the case in this study with the codon 59 alpha chain variant provides a further example illustrating the spectrum of phenotypes associated with the alpha-thalassemic hemoglobinopathies.- - - - - - - - - - ranking = 4778069.0747364keywords = alpha-thalassemia, h (Clic here for more details about this article) |
9/136. Hb Sallanches [alpha104(G11)Cys-->Tyr]: a rare alpha2-globin chain variant found in the homozygous state in three members of a Pakistani family.We have identified a rare alpha2-globin chain variant, Hb Sallanches [alpha104(G11) Cys-->Tyr], in a Pakistani family having three homozygous patients with transfusion-dependent Hb H disease. This variant, previously reported in a French patient and a West Indian homozygous patient with Hb H disease, is due to a mutation at codon 104 (TGC-->TAC). This is the third case of Hb Sallanches and the first case with three homozygous patients reported in pakistan. Due to the different ethnic origins of the patients, it is very likely an independent mutation.- - - - - - - - - - ranking = 1.2682926829268keywords = h (Clic here for more details about this article) |
10/136. An infant with severe combined immunodeficiency syndrome, an alpha-thalassemia trait and renal fanconi syndrome.We describe an infant with severe combined immunodeficiency syndrome and an alpha-thalassemia trait who developed a renal fanconi syndrome after his first stem cell transplantation. This syndrome consists of a generalized failure of proximal tubular reabsorption, which leads to a large number of metabolic disturbances. The etiology varies from inherited causes, including an idiopathic form, to acquired causes such as intoxications, immunological disorders and hemoglobinopathies. In this case report we discuss possible explanations of the fanconi syndrome in our patient.- - - - - - - - - - ranking = 1990861.3441483keywords = alpha-thalassemia, h (Clic here for more details about this article) |
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