1/353. 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 = thalassemia (Clic here for more details about this article) |
2/353. 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 = 1keywords = thalassemia (Clic here for more details about this article) |
3/353. 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 = 0.66666666666667keywords = thalassemia (Clic here for more details about this article) |
4/353. 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 = 0.66666666666667keywords = thalassemia (Clic here for more details about this article) |
5/353. 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 = 0.77777777777778keywords = thalassemia (Clic here for more details about this article) |
6/353. A new glucose 6 phosphate dehydrogenase variant G6PD Sinnai (34 G-->T). Mutations in brief no. 156. Online.In this paper we report a male infant heterozygous for thalassemia with a mild glucose 6 phosphate dehydrogenase deficiency. The molecular basis of this new Class III G6PD variant is a G-->T mutation at nucleotide 34 in the exon 2, which predicts a Val-->Leu aminoacid substitution at codon 12. We designated this variant as G6PD Sinnai from the place of birth of the propositus.- - - - - - - - - - ranking = 0.11111111111111keywords = thalassemia (Clic here for more details about this article) |
7/353. 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 = 0.11111111111111keywords = thalassemia (Clic here for more details about this article) |
8/353. 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 = 1.4444444444444keywords = thalassemia (Clic here for more details about this article) |
9/353. A case of pulmonary thromboembolism in thalassemia intermedia: are these patients at risk for thrombotic events?We describe a case of pulmonary thromboembolism in a 48-year-old woman with thalassemia intermedia and no other risk factors. Multiple bilateral defects were detected by perfusion lung scan. No sources of emboli were detected, despite extensive evaluation. We suggest that a chronic hypercoagulable state due to multiple coagulation alterations might be a cause of thromboembolic events in thalassemia intermedia patients, even when no other risk factors are present.- - - - - - - - - - ranking = 0.66666666666667keywords = thalassemia (Clic here for more details about this article) |
10/353. Familial-skewed X-chromosome inactivation as a predisposing factor for late-onset X-linked sideroblastic anemia in carrier females.X-linked sideroblastic anemia (XLSA) is caused by mutations in the erythroid-specific 5-aminolevulinic acid synthase (ALAS2) gene. An elderly woman who presented with an acquired sideroblastic anemia is studied. Molecular analysis revealed that she was heterozygous for a missense mutation in the ALAS2 gene, but she expressed only the mutated gene in reticulocytes. Her 2 daughters and a granddaughter were heterozygous for this mutation, had normal hemoglobin levels, and expressed the normal ALAS2 gene in reticulocytes. A grandson with a previous diagnosis of thalassemia intermedia was found to be hemizygous for the ALAS2 mutation. Treatment with pyridoxine completely corrected the anemia both in the proband and her grandson. All women who were analyzed in this family showed skewed X-chromosome inactivation in leukocytes, which indicated a hereditary condition associated with unbalanced lyonization. Because the preferentially active x chromosome carried the mutant ALAS2 allele, acquired skewing in the elderly likely worsened the genetic condition and abolished the normal ALAS2 allele expression in the proband. (blood. 2000;96:4363-4365)- - - - - - - - - - ranking = 0.11111111111111keywords = thalassemia (Clic here for more details about this article) |
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