Absence of JAK2 V617F mutation in thalassemia intermedia patients.

JAK2 is a cytoplasmic tyrosine kinase that has a vital role in signal transduction from several hemopoietic growth factor receptors. The JAK2 V617F mutation has been implicated in a variety of diseases mainly related to myeloproliferative disorders including polycythemia Vera, essential thrombocythemia, and idiopathic Myelofibrosis but has not been previously described in Thalassemia patients. We studied 36 Lebanese patients diagnosed with thalassemia intermedia and assessed the presence or absence of the JAK2 V617F mutation using JAK2 activating mutation assay (In VivoScribe Technologies) and Polymerase Chain Reaction (PCR). None of the thalassemia intermedia patients were positive for this mutation. To our knowledge, this study is the first to determine the status of JAK2 V617F mutation in thalassemia intermedia patients and expands the international published literature on JAK2. The latter's V617F mutation does not seem to play a role in this hematologically important clinical entity.

Prevalence of the prothrombin G20210A polymorphism in the Lebanese population: use of a reverse hybridization strip assay approach.

The factor II (prothrombin) G20210A gene polymorphism is the second most common SNP reported in VTE where it is associated with elevated plasma prothrombin levels and with a 3-fold increased risk. We studied the distribution of the G/G, G/A, and A/A genotypes of the Prothrombin G20210A gene mutation in the general Lebanese population using a novel technique in order to assess their prevalence, compare the results to previously reported data and to describe an available method that will permit easy and fast identification of the mutation. Prothrombin different genotypes were determined using the Cardiovascular Disease (CVD) StripAssay which is based on a Polymerase Chain Reaction-Reverse hybridization technique and DNA from 205 unrelated healthy donors from our HLA-bank was used. The prevalence of G/G, G/A, and A/A genotypes was found to be 98.54, 1.46, and 0%, respectively, with G and A allelic frequency of 99 and 1%, respectively. The sampled Lebanese population showed prothrombin genotypes distribution similar to Caucasians, and our results are comparable to other reports on the Lebanese healthy individuals. However, this is the first report on the prevalence of prothrombin G20210A mutation using this technique. Our results suggest that this approach is reliable and can be used as an assessment for thrombophilia profile. In addition, future investigations should be conducted to assess the contribution of the prothrombin G20210A mutation, on its own and in collaboration with other factors, in various clinical entities notably VTE.

Killer cell immunoglobulin-like receptor (KIR) genotypes in patients with recurrent tonsillitis.

AIMS: This study represents the first report on the distribution of killer cell immunoglobulin-like receptor (KIR) genotype among recurrent tonsillitis patients. We recruited 34 Lebanese pediatric patients diagnosed with recurrent tonsillitis and had their DNA typed using sequence-specific primer technique for the presence of 16 KIR loci. RESULTS: We observed that 25 different KIR genotypes were present similar to the general control population with the same KIR gene content. There was no statistically significant difference in the distribution of the activating and inhibitory KIR genes between the two categories. Like in the general control population, we noted a predominance of the AB genotype; however, the KIR genotypic distribution among the tonsillitis patients was much more heterogeneous with even new genotypes not reported in the control group. CONCLUSIONS: Although the sample size is small, this first study observes an interesting heterogeneous KIR gene profile in recurrent tonsillitis that warrants larger and further research in the area for the true biological and clinical significance of this observation.

HLA class I allele frequencies in the Lebanese population.

The highly polymorphic Human Leukocyte Antigen system encompasses different loci that have been studied in transplantation as well as diseases and population associated research. This study is the first and largest of its kind to describe the distribution of HLA-A, -B and -C alleles in Lebanon. Respectively, 1994, 1309 and 1163 Lebanese individuals referred for HLA typing and possible bone marrow/kidney donation were tested for HLA-A, HLA-B and HLA-C alleles using the polymerase chain reaction/Sequence specific priming (PCR-SSP) method. Our data were compared to that of several populations with interesting and common findings shared with the Moroccan, Jordanian, Tunisian, Omani, Korean, Chinese, Japanese, Peruan, Bulgarian, Irish, Polish, Spanish, Swiss, American, African and Brazilian populations. The following data concerning the Lebanese population will help future investigators to study the relation of HLA-A, -B and -C alleles with common diseases in Lebanon and will add to the available international literature. This new data will serve as a major reference report in the region.

HLA class II allele frequencies in the Lebanese population.

AIMS: Being one of the most polymorphic genetic systems , the Human Leukocyte Antigen system is divided into class I (HLA-A, HLA-B and HLA-C) and class II (HLA-DP, -DQ and -DR). This study is the first and largest of its kind to describe the distribution of HLA-DQB1 and HLA-DRB1 alleles in Lebanon and the region. METHODS: Respectively, 560 and 563 Lebanese individuals referred for HLA typing and possible bone marrow/kidney donation were tested for HLA-DQB1 and HLA-DRB1 alleles using the polymerase chain reaction/sequence specific priming (PCR-SSP) method. RESULTS: Our data were compared to that of several populations with interesting common findings between the Lebanese, Jordanian, Bahraini, Saudi, Kuwaiti, Tunisian, Korean, Japanese, Thai, Irish, Bulgarian and Polish populations. CONCLUSION: These data about the Lebanese population are going to aid future researchers to study the relation of HLA-DQB1 and HLA-DRB1 alleles with major and common diseases in the Lebanese population and will add to the available international literature associated with these loci. In addition it will serve as a reference for the future national bone marrow registry program in our country. We also reviewed the literature for the described association between HLA-DRB1 and -DQB1 loci and different disease entities.

JAK2 V617F mutation detection: laboratory comparison of two kits using RFLP and qPCR.

AIM: The JAK2 V617F mutation has been implicated in a variety of diseases mainly related to myeloproliferative disorders including polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis with an increased demand for testing using molecular techniques. The latter are diversified and all aim to simplify the methods employed for detection. MATERIALS AND METHODS: In this study, two detection kits were compared: one using polymerase chain reaction (PCR)-restriction fragment length polymorphisms (RFLP) (JAK2 Activating Mutation assay; InVivoScribe Technologies, San Diego, CA) and the other using real-time quantitative PCR (JAK2 MutaScreen Kit assay; Ipsogen, Marseilles, France). RESULTS: A total of 80 reactions were compared using the two techniques and the results showed a perfect concordance between the two methods. CONCLUSION: We conclude that both PCR-RFLP and quantitative PCR are extremely useful and sensitive techniques for the detection of the JAK2 V617F mutation with quantitative PCR being more time effective and less expensive.

Killer cell immunoglobulin-like receptor genotypes in Behçet's disease patients: any role for the 3DP1*001/002 pseudogene?

AIMS: Genotypic profiles of the natural killer cell immunoglobulin-like receptors (KIR) have been reported to vary among different ethnic groups and variable clinical entities. This study represents the second report on its distribution among patients with Behçet's disease (BD). We studied 43 unrelated Lebanese Behçet's patients, had their DNA typed using sequence-specific primer technique for the presence of 16 KIR genes and pseudogenes loci, and compared them to the general Lebanese population. RESULTS: In addition to sharing common features with the general population, the AA genotype was still the most frequent--however, with five new KIR profiles identified. There was no statistically significant distribution of the different KIR genes between the cases (BD patients) and controls (Lebanese population); however, KIR3DP1*001/002 was found to be significantly different between the BD patients and the Lebanese population, but this significance was lost after correction for all KIR loci. CONCLUSION: The results lead to an interesting future research question of whether or not KIR genotype is involved in the predisposition to or pathogenesis of BD especially that a pseudogene is controversially in question. This is the second report that describes the KIR genotypic profile in such an important clinical disease but the first to shed a light on the possible role of a pseudogene.