JAK2 V617F "indeterminate" results by MutaScreen can be easily resolved using MutaQuant kits.

AIM: Janus kinase 2 (JAK2) V617F mutation testing has revolutionized the classification of myeloproliferative disorders, for which several tests have been introduced for qualitative and quantitative diagnostics including the MutaScreen and MutaQuant kits by IPSOGEN. One interesting technical observation are those values detected by MutaScreen kits, which have typically "indeterminate" meaning at a provided reference strand cutoff point and cannot be classified as either positive or negative for JAK2 V617F mutation. RESULTS: We ran 10 different patients with such a finding using the MutaQuant kit and got a better resolution and interpretation into clear-cut negative or positive cases, which were also clinically followed and confirmed as being nonmyeloproliferative or myeloproliferative entities, respectively. CONCLUSION: We propose that it is important to not consider the indeterminate or "at-the-reference strand" results obtained by MutaScreen as positive but rather perform additional testing using MutaQuant kits or other JAK2 quantitative assays. For laboratories that can afford it and utilize both assays, it may be a better strategy to directly initiate diagnostic testing using the MutaQuant rather than the MutaScreen kit.

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.

Plasminogen Activator Inhibitor-1 (PAI-1) gene 4G/5G alleles frequency distribution in the Lebanese population.

Plasminogen activator inhibitor-1 (PAI-1) is an inhibitor of fibrinolysis. Increased plasma PAI-1 levels play an essential role in the pathogenesis of cardiovascular risk and other diseases associated with thrombosis. The 4G/5G polymorphism of the PAI-1 promoter region has been extensively studied in different populations. We studied 160 healthy unrelated Lebanese individuals using a reverse hybridization PCR assay to detect the 5G/5G, 4G/5G and, 4G/4G genotypes of the PAI-1 gene and the frequencies of the 4G and 5G alleles. We found that 4G/5G genotype was the most prevalent (45.6%) followed by 5G/5G (36.9%) and 4G/4G (17.5%). The frequencies of the 4G and 5G alleles were calculated to be 0.403 and 0.597, respectively. Compared to other ethnic communities, the Lebanese population was found to harbour a relatively high prevalence of the rare 4G allele. This, in turn, may predispose this population to develop cardiovascular diseases and other thrombotic clinical conditions. This study aids to enhance our understanding of the genetic features of the Lebanese population.

MEFV gene mutations spectrum among Lebanese patients referred for Familial Mediterranean Fever work-up: experience of a major tertiary care center.

Familial Mediterranean Fever (FMF) is an autosomal recessive inflammatory disorder predominantly affecting people living in or originating from areas around the Mediterranean Sea, mainly Jews, Armenians, Turks, and Arabs. It is characterized by recurrent attacks of inflammation of serosal membranes and fever resulting in acute abdominal, chest, or joint pain. Over 50 MEditerranean FeVer (MEFV) mutations and polymorphisms have been identified in FMF patients. The objective of this study was to analyze the distribution and frequencies of 12 MEFV mutations in 266 referred Lebanese patients using a reverse-hybridization assay. Of the 266 patients, 129 (48.5%) were positive for at least one mutation and 137 (51.5%) had no mutations detected. Of the 129 patients with mutations, 35 were homozygous, 41 were compound heterozygous and 53 were heterozygous. The five most common mutations M694V, E148Q, V726A, M694I and M680I (G/C) accounted for 26.1, 22.2, 21.3, 9.6 and 7.7%, respectively. The A744S, F479L, R761H and I692del were encountered in 2.9% of patients; P369S and M680I (G/A) were found in 1.2% of patients while K695R was absent. The spectrum of the MEFV mutations among our sampled Lebanese FMF patients shows the high heterogeneity at the allelic level when compared to Arab and non-Arab populations. The most important feature was the relatively high frequency of the E148Q in our study group that allows us to question it as a mutation rather than a polymorphism. Further studies should be conducted to evaluate the role of the E148Q allele.

Frequency distribution of the G/A alleles of the beta-fibrinogen gene in the Lebanese population.

Fibrinogen is a plasma protein that has been reported to be associated with an increased risk of atherothrombotic diseases and venous thrombosis. The most common polymorphism that has been studied so far in different populations is the G-455-->A polymorphism in the promoter region of the beta-fibrinogen gene. We studied 160 healthy unrelated Lebanese individuals for the prevalence of -455G/G, -455G/A and -455A/A genotypes of the beta-fibrinogen gene and the frequency of G and A alleles using a reverse hybridization PCR assay. The prevalence of the G/G, G/A, and A/A genotypes were found to be 60.6, 31.9 and 7.5%, respectively. The frequency of the G and A alleles were found to be 0.77 and 0.23, respectively. As compared to other ethnic groups, the Lebanese individuals were found to have a relatively high prevalence of the A allele which may predispose them to develop cardiovascular diseases as well as thrombotic events. This study provides additional unique genetic information pertaining to the Lebanese population.

Factor XIII gene V34L mutation in the Lebanese population: another unique feature in this community?

We studied the distribution of the Factor XIII gene V34L polymorphism in a sample of healthy Lebanese individuals to assess its prevalence and compare it with other populations. Factor XIII genotypes were determined using the Cardiovascular Disease (CVD) StripAssay (ViennaLab, Austria), which is based on a Polymerase Chain Reaction-Reverse hybridization technique. DNA from 205 unrelated healthy donors from our HLA database was used. The prevalence of Wild type, heterozygous, and homozygous genotypes was found to be 74.2%, 22.4%, and 3.4% respectively. The sampled Lebanese population showed that the prevalence of V34L carriers (25.8%) was lower than Caucasians in general (44.3%) and, interestingly, with a low allele frequency of 0.14 similar to that in Blacks and South Asians. This first report from Lebanon sheds light on an additional unique genetic feature of this population and will prospectively serve as a baseline statistical data for future investigations of the prevalence of Factor XIII V34L mutation in association with various clinical entities notably cardiovascular diseases.