1,721,005 research outputs found
Association of α globin gene quadruplication and heterozygous β thalassemia in patients with thalassemia intermedia
No full textTen patients with thalassemia intermedia with variable
severity and apparent simple heterozygosis for b0 39 C>T
nonsense mutation were submitted to clinical, hematologic
and molecular studies. The presence of an unknown
molecular defect (silent b-thalassemia) unlinked to the b
cluster interacting with the heterozygous b thalassemia,
was previously postulated in these families. Analysis of the
a globin gene cluster with PCR-based methods (MLPA,
GAP-PCR, digestion with restriction enzymes) detected
complex rearrangements in the a cluster. A duplication of
the a globin gene locus, including the upstream regulatory
region, was present in all the patients, associated in some
of them with deletion or non-deletion a thalassemia. The
variability of the clinical phenotype correlates with the
degree of the globin chain imbalance. The presence of a
globin cluster duplication should be considered in patients
heterozygote for b-thalassemia with thalassemia intermedia
phenotype and in the carriers of suspected silent b thalassemia.
Key words: thalassemia intermedia, a-globin gene quadruplication,
silent b thalassemia, MLPA.
Citation: Sollaino MC, Paglietti ME, Perseu L, Giagu N, Loi D,
and Galanello R. Association of a globin gene quadruplication
and heterozygous b thalassemia in patients with thalassemia
intermedia. Haematologica 2009.94:1445-1448.
doi: 10.3324/haematol.2009.005728
©2009 Ferrata Storti Foundation. This is an open-access paper
Delayed fetal hemoglobin switching in subjects with KLF1 gene mutation.
No full textVariations at the KLF1 gene have been associated with a series of human erythroid phenotypes including the In-(Lu) phenotype, hereditary persistence of fetal hemoglobin, congenital dyserythropoietic anemia, borderline HbA2 and increased red blood cell protoporphyrin.Natural mutations have shown that KLF1 regulates gamma globin gene expression and its role in the switching from fetal to adult globin expression has been suggested by experimental studies.In this paper we report that subjects with S270X KLF1 mutations show a decrease of HbF levels with increasing age, supporting in vivo the role of KLF1 in hemoglobin switching in humans
Somatic deletion of the normal beta-globin gene leading to thalassaemia intermedia in heterozygous beta-thalassaemic patients
No full textTwo beta-thalassaemia patients, whose constitutive genotype was beta(39C)/beta(39C-->T), had the clinical phenotype beta-thalassaemia intermedia. Analysis of leucocyte DNA showed the presence of the mutated beta(39C-->T)-gene exclusively, while the normal beta(39C)-gene was also present in reticulocyte RNA. Deletional analysis of chromosome 11p15.5 on leucocyte DNA showed large deletions including the beta-globin gene. Two populations of erythroid progenitors, one heterozygous and the other hemizygous for the beta(39C-->T) mutation, were demonstrated in one case. This confirms that, in heterozygous individuals, beta-thalassaemia intermedia may be caused by inactivation of the beta-locus in trans as a result of chromosome 11p15.5 deletions in a subpopulation of haematopoietic cell
Hemoglobin Belfast (beta15,Trp→Arg) definition of the clinical and hematological phenotype
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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