1/323. A new alkali-resistant hemoglobin alpha2J Oxford gammaF2 in a Sicilian baby girl with homozygous beta0 thalassemia.A 10-mo-old baby girl with homozygous beta0 thalassemia and alphaJOxford, presenting the clinical picture of homozygous beta thalassemia is described. Hemoglobin electrophoresis showed three bands: the first two with the mobilities of hemoglobin Hb A2 (1%) and Hb F (69%), respectively, the third migrating a little faster than Hb A (30%). About 30% of her alpha chains were J Oxford which, bound to her gamma chains, produced a new alkali-resistant hemoglobin, alpha2 J Oxford gamma F2, which has not been described previously. Hemoglobin synthesis in vitro showed the absence of beta chain synthesis and an alpha/non-alpha ratio of 2. The patient's father was heterozygous for both the Hb J Oxford and beta0 thalassemia genes, the mother a carrier of beta0 thalassemia; four other relatives were carriers of Hb J Oxford, and one was a carrier of beta thalassemia.- - - - - - - - - - ranking = 1keywords = beta (Clic here for more details about this article) |
2/323. The association of Hb Khartoum [beta124(H2)Pro-->Arg] with gamma -thalassemia is responsible for hemolytic disease in the newborn of a Sudanese family.The unstable Hb Khartoum with a Pro-->Arg replacement at position beta124 was identified by isoelectrofocusing, high performance liquid chromatography, and peptide mapping in a mother and two male children of a Sudanese family. All three were heterozygous for the abnormal hemoglobin; the father and a third male child did not carry the mutation. The mother was also homozygous for two putative gamma -thalassemia point mutations, one affecting both Agamma and Ggamma genes at IVS-II-115 (A-->G), and one affecting the Ggamma gene at the 3' untranslated region (-A) at position -6 from the polyadenylation site. The father had normal gamma genes. All three children were heterozygous for both the gamma -thalassemia mutations. The two older children, who were compound heterozygotes for Hb Khartoum/gamma -thalassemia, presented at birth with severe neonatal jaundice which necessitated exchange blood transfusions. Other causes of neonatal jaundice were excluded. The third male child, who did not carry the Hb Khartoum anomaly but was heterozygous for gamma -thalassemia, did not develop neonatal jaundice. It is concluded that the instability of Hb Khartoum in combination with gamma -thalassemia is responsible for neonatal hemolytic anemia in this family.- - - - - - - - - - ranking = 0.5keywords = beta (Clic here for more details about this article) |
3/323. prenatal diagnosis of heterozygous beta-thalassemia.The parents of a child with homozygous thalassemia of the beta O variety requested prenatal diagnosis during a subsequent pregnancy. At the 19th week of pregnancy, a sample of blood containing fetal cells was obtained by placentocentesis. Radiochromatography of globin chains demonstrated production of a beta-chain with a beta/gamma synthetic ratio of 0.049, which is low for this gestational age. The conclusion that the child would be heterozygous for the beta-thalassemia gene was confirmed after birth.- - - - - - - - - - ranking = 0.8keywords = beta (Clic here for more details about this article) |
4/323. Hemoglobin Riyadh--alpha2beta2 (120(GH3)Lys replaced by Asn). A new variant found in association with alpha-thalassemia and iron deficiency.On a field trip toSaudi arabia (M.A.F.E.H.) in which the relationship between alpha-thalassemia and iron deficiency was studied, a fast moving hemoglobin variant was noted in a 30 year old Saudi Arabian woman. Analysis of the hemoglobin variant showed that the amino acid substitution was beta120 Lys replaced by Asn. This variant had not been described previously and has been named Hb Riyadh. There was also present an alpha-thalassemia and details are given of the imbalance of globin chain synthesis. It was possible to improve considerably the balance in vitro by the addition of hemin.- - - - - - - - - - ranking = 0.5keywords = beta (Clic here for more details about this article) |
5/323. Hematological and hemoglobin synthesis studies in a family with deltabeta-thalassemia trait.A Basque Spanish family with heterozygous deltabeta-thalassemia is described. patients with this anomaly usually present hematological findings observed in classical beta-thalassemia, but clinical conditions and unbalanced chain synthesis are less severe. Our propositus, however, presented clinical and biosynthetic data similar to those described in thalassemia intermedia. A family study was also performed.- - - - - - - - - - ranking = 0.6keywords = beta (Clic here for more details about this article) |
6/323. Mapping of a syndrome of X-linked thrombocytopenia with Thalassemia to band Xp11-12: further evidence of genetic heterogeneity of X-linked thrombocytopenia.X-linked thrombocytopenia with thalassemia (XLTT; Online Mendelian Inheritance in Man [OMIM] accession number 314050) is a rare disorder characterized by thrombocytopenia, platelet dysfunction, splenomegaly, reticulocytosis, and unbalanced hemoglobin chain synthesis. In a 4-generation family, the gene responsible for XLTT was mapped to the x chromosome, short arm, bands 11-12 (band Xp11-12). The maximum lod score possible in this family, 2.39, was obtained for markers DXS8054 and DXS1003, at a recombination fraction of 0. Recombination events observed for XLTT and markers DXS8080 and DXS8023 or DXS991 define a critical region that is less than or equal to 7.65 KcM and contains the gene responsible for the wiskott-aldrich syndrome (WAS; OMIM accession number 301000) and its allelic variant X-linked thrombocytopenia (XLT; OMIM accession number 313900). Manifestations of WAS include thrombocytopenia, eczema, and immunodeficiency. In WAS/XLT the platelets are usually small, and bleeding is proportional to the degree of thrombocytopenia. In contrast, in XLTT the platelet morphology is normal, and the bleeding time is disproportionately prolonged. In this study no alteration in the WAS gene was detected by Northern blot or Western blot analysis, flow cytometry, or complimentary dna dideoxynucleotide fingerprinting or sequencing. As has been reported for WAS and some cases of XLT, almost total inactivation of the XLTT gene-bearing x chromosome was observed in granulocytes and peripheral blood mononuclear cells from 1 asymptomatic obligate carrier. The XLTT carrier previously found to have an elevated alpha:beta hemoglobin chain ratio had a skewed, but not clonal, X-inactivation pattern favoring activity of the abnormal allele. Clinical differences and results of the mutation analyses make it very unlikely that XLTT is another allelic variant of WAS/XLT and strongly suggest that X-linked thrombocytopenia mapping to band Xp11-12 is a genetically heterogeneous disorder.- - - - - - - - - - ranking = 0.1keywords = beta (Clic here for more details about this article) |
7/323. beta-thalassemia intermedia caused by compound heterozygosity for Hb Malay (beta codon 19 AAC-->AGC; asn-->Ser) and codons 41/42 (-CTTT) beta(0)-thalassemia mutation.We report a case of beta-thalassemia intermedia caused by compound heterozygosity for hemoglobin (Hb) Malay and codon 41/42 (-CTTT) beta(0)-thalassemia mutation in a 38-year-old Chinese woman. This patient has long-standing anemia with a baseline Hb level of around 70 g/L. She worked as a full-time cashier and had not required regular blood transfusions. Nevertheless, she had splenomegaly necessitating splenectomy, cholelithiasis, and iron overload. This case illustrates the varied phenotypic expression associated with compound heterozygosity for Hb Malay and other beta-thalassemia mutations. Since Hb Malay migrates as Hb A on electrophoresis and chromatography, this variant Hb mutation ought to be included in the differential diagnosis for beta-thalassemia major or intermedia patients of Southeast Asian descent who are reported to have Hb A on the basis of Hb analysis. The possible presence of this mutation should also be considered in appropriate cases for genetic counseling in couples at risk of conceiving fetuses with beta-thalassemia major or intermedia.- - - - - - - - - - ranking = 1.7keywords = beta (Clic here for more details about this article) |
8/323. spinal cord compression due to extramedullary haematopoiesis in two patients with thalassaemia: complete regression with blood transfusion therapy.Extramedullary haematopoiesis, a common finding in thalassaemia, is rarely localized in the spinal cord and even more rarely has neurological manifestations. We present two patients suffering from thalassaemia (intermedia and beta homozygous) and paraparesis due to spinal cord compression from intrathoracic extramedullary haematopoietic masses. Diagnosis was based on magnetic resonance imaging findings, and treatment consisted of blood hypertransfusions. The majority of published cases have been successfully treated by radiation and in some cases by blood transfusions. Our two patients completely recovered, and there has been no recurrence during the 4 years since their treatment. Diagnosis and treatment of this rare condition are discussed.- - - - - - - - - - ranking = 0.1keywords = beta (Clic here for more details about this article) |
9/323. The beta-globin genotype E121Q/W15X (cd121GAA-->CAA/cd15TGG-->TGA) underlines Hb d/beta-(0) thalassaemia marked by domination of haemoglobin D.Among 13,525 haemoglobin analyses performed in our laboratory we detected 21 cases of haemoglobin D (Hb D) disease. Investigation of a family affected with this abnormal haemoglobin revealed two cases of Hb D/beta-(0) thalassaemia for the first time among Saudi arabs. The two patients were diagnosed as having chronic haemolytic anaemia of moderate severity on the basis of the haemoglobin level, haematocrit, mean corpuscular haemoglobin, mean corpuscular volume, reticulocyte count, red blood cell count microscopy, elevated serum conjugated and non-conjugated bilirubin, increased serum lactic dehydrogenase, and the occasional need for blood transfusions. Genetic analysis enabled the detection of compound heterozygosity for the missense E121Q (codon 121 GAA-->CAA) and stop W15X (codon 15 TGG-->TGA) mutations as causative of the clinical phenotype of Hb D-LosAngeles (Punjab)/beta-(0) thalassaemia. The disease manifested as domination of Hb D and moderate haemolytic anaemia. The co-inheritance of beta-(0) thalassaemia seems to be responsible for conferring the deleterious effect on the presentation of Hb D disease in these patients. The present result emphasizes the significance of molecular testing in resolving certain diagnostic ambiguities in haematology as in cases of heterozygous Hb D in association with beta-(0) thalassaemia which, by haemoglobin electrophoresis, may be misdiagnosed as Hb D homozygosity.- - - - - - - - - - ranking = 1.2keywords = beta (Clic here for more details about this article) |
10/323. 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.- - - - - - - - - - ranking = 2keywords = beta (Clic here for more details about this article) |
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