Néstor Walter Soria

Clinical significance of V617F mutation of the JAK2 gene in patients with chronic myeloproliferative disorders.

Abstract Objective: To determine the prevalence of JAK2 V617F mutation and its clinical correlation in patients with chronic myeloproliferative disorders (CMD): polycythemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (IMF). Materials and methods: Detection of JAK2 V617F mutation by allele specific-PCR. Results: One hundred and three patients with CMD were included in the study. JAK2 V617F distribution was PV 40/45 (89%), ET 30/43 (69%), and IMF 7/15 (47%). In PV and ET patients only, 18 had thrombosis at diagnosis and 12 during follow-up (these were microvascular: 11, venous: 7 and arterial: 12); of these 28/70 (40%) were JAK2pos versus 2/18 (11%) JAK2neg; P=0·02. In a median of 4 years, two patients with PV JAK2pos evolved to myelofibrosis and one patient with PV presented in leukemic transformation (JAK2pos before and after transformation); six patients died: four patients with IMF and two patients with PV. Conclusions: We found an association between JAK2 V617F and thrombotic events in patients with PV and ET.

β-thalassemia and hemoglobin types in Argentina: Determination of most frequent mutations

In order to know the spectrum of β‐thalassemia alleles and other mutations affecting the β‐globin gene, we analyzed the hemoglobin abnormalities in 24 patients from the Province of Córdoba in Argentina. Molecular screening of samples was performed by the polymerase chain reaction (PCR), using six sets of oligonucleotides to amplify fragments encompassing the whole β‐globin coding region and splice junctions, as well as the promoter and 3′ untranslated regions. The altered fragments were determined by denaturing gradient gel electrophoresis (DGGE), and the corresponding mutations were identified by restriction enzyme analysis or by direct sequencing of PCR products. Using this approach, three different β‐thalassemia mutations were detected, codon 39 (C→T), IVS‐1‐110 (G→A), and IVS‐1‐1 (G→A), and also the hemoglobin S trait. This is the first report of β‐thalassemia mutations described in Argentina. Our results show that these mutations are similar to those found in Spain and Italy, possibly due to the important Mediterranean migratory stream received in our country, and could be important for prenatal diagnosis of these diseases in Córdoba, Argentina. Am. J. Hematol. 54:160–163, 1997

Analysis of C282Y and H63D mutations of the hemochromatosis gene (HFE) in blood donors from Córdoba, Argentina.

Dear Editor, Hereditary hemochromatosis (HH) is an autosomal recessive disease, characterized by an increase in the intestinal absorption of iron. It is one of the most common genetic disorders in Europe, with an estimated prevalence of 1 in 200 in the northern European populations of Nordic or Celtic ancestry [1, 2]. The distribution of HH seems to be related to migratory and social movements from Europe to the rest of the world. The diagnosis of HH has been previously based on the demonstration of iron overload in blood tests and liver biopsies. In 1996, the hemochromatosis gene (HFE) was identified in the short arm of chromosome 6. Two mutations were found in this gene (C282Y and H63D), which have been considered to be responsible for most of the HH cases. The discovery changed both the concept and the clinical handling of the disease, facilitating the diagnosis [3, 4]. Genetic inheritance results from continuous racial interactions due to population migration throughout history. In Mediterranean countries, such as Italy, France, Portugal, and Spain, frequencies of HFE altered allele gene are higher in the north compared with that in the rest of the country, consistent with invader waves and origins of different civilizations [5–8]. There are no reports on the frequency of C282Y and H63D mutations in the Argentina. The present study was performed on a population sample of the central area of Argentina, which received an important contribution of European immigration mainly of Italian and Spanish origin. Similar pattern of immigrations occurred in different South American countries. The aim of this study was to estimate the frequencies of the C282Y and H63D mutations of the HFE gene in a population from Argentina. A total of 421 apparently healthy adult blood donors, randomly selected from Córdoba (Argentina), were assayed for C282Y and H63D mutations in the HFE gene. There were 191 men and 230 women (mean age 38.6 years, age range 22–65 years). The study was approved by the University Committee of Ethics and Research. In all cases, the subjects were informed and their consent was obtained. Total DNA was extracted from peripheral blood using standard procedures [9]. DNA fragment amplifications of the HFE gene were carried out by polymerase chain reaction using primers previously designed by Lynas [10]. For the C282Y mutation, the amplified product (380 bp) was digested by the restriction enzyme RsaI (New England BioLabs) with a target sequence (GT↓AC) located on the mutated allele. In the case of the H63D mutation, the amplified fragment of 208 bp was digested by the restriction enzyme Bcl I (New England BioLabs) with the sequence target (T↓GATCA) located in the wild-type allele. The digested products were separated by electrophoresis in agarose gel (3% p/v) and visualized by ethidium bromide staining. Allelic frequencies were determined and statistical analysis was performed using the chi-square (χ) test. The frequencies of C282Y and H63D mutations in the HFE gene were evaluated in a sample of 421 healthy Argentinean subjects, representative of the population of the central Ann Hematol (2009) 88:77–79 DOI 10.1007/s00277-008-0532-6