Varied Prevalence of Factor V G1691A (Leiden) and Prothrombin G20210A Single Nucleotide Polymorphisms Among Arabs

High prevalence of factor V Leiden and prothrombin G20101A mutations in Kashmiri patients with venous thromboembolism

AIM

The genetic variants of the factor V (G1691A), prothrombin (G20210A) and MTHFR (C677T) genes have been widely implicated as inherited risk factors for developing venous thrombosis. This study was undertaken to reveal the frequency of these mutations in Kashmiri patients with venous thromboembolism.

METHODOLOGY

A case-control study was designed with 250 VTE patients and 250 healthy controls. The mutations were analysed using ARMS-PCR and PCR-RFLP approach.

RESULT

The factor V Leiden G1691A mutation was found in 17/250 (6.8%) VTE patients and prothrombin G20210A mutation was found in 7/250 (2.8%) VTE patients while no mutation was found in any of the healthy controls. Both the mutations were found to be significantly associated with the increased risk of VTE (p = 0.0001 and 0.0150 respectively) while no association of VTE risk with MTHFR C677T polymorphism was found (p = 0.53).

CONCLUSION

The increased frequency of factor V Leiden G1691A and prothrombin G20210A mutation in VTE patients indicates a significant role of these mutations in the development of VTE in our population. We therefore suggest the routine screening of these two mutations as thrombophilic markers in Kashmiri patients with venous thromboembolism.

Association of Factor V Leiden and Prothrombin G20210A Polymorphisms in Women with Recurrent Pregnancy Loss in Isfahan Province, Iran

Background:

Maternal thrombophilia has been identified as a risk factor for recurrent pregnancy loss (RPL). The aim of this study was to investigate the association between prothrombin G20210A and factor V Leiden (FVL) polymorphisms in women with RPL and a control group of parous women in Isfahan province of Iran.

Methods:

We studied 250 women with idiopathic RPL and 116 control cases. Prothrombin and FVL different genotypes were determined using polymerase chain reaction and reverse hybridization technique.

Results:

The frequencies of heterozygous mutation prothrombin G20210A were 6% and 0.9%, respectively (P = 0.025), in cases compared to the control group. The frequencies of homozygous mutation prothrombin G20210A were 0.4% and 0%, respectively, in cases compared to controls (P = 0.02). The prothrombin mutation was significantly higher in cases compared to the control group (odds ratio 8.81; 95% confidence interval: 1.16–66.62). There was no significant difference between the FVL mutation and pregnancy loss.

Conclusions:

The results indicated a significant higher frequency of prothrombin G20210A in women with RPL in comparison with controls. Our data suggest that the prothrombin G20210A mutation, but not the FVL mutation, may be an unrecognized cause of RPL in our population.

Factor V Leiden G1691A and prothrombin G20210A mutations among Palestinian patients with sickle cell disease

Background

Vascular thrombosis is an important pathophysiological aspect of sickle cell disease (SCD). This study aimed to investigate the prevalence and clinical impact of factor V Leiden G1691A (FVL) and prothrombin G20210A mutations among Palestinian sickle cell disease (SCD) patients.

Methods

A total of 117 SCD patients, including 59 patients with sickle cell anemia (SS), 33 patients with sickle β-thalassemia and 25 individuals with sickle cell trait (AS) were studied. The control group consisted of 118 healthy individuals. FVL and prothrombin G20210A mutations were determined by RFLP PCR.

Results

Analysis of the clinical history of SCD patients revealed that seven patients have had vascular complications such as ischemic stroke or deep vein thrombosis. In SCD patients, the inheritance of the FVL mutation showed a significantly higher incidence of pain in joints, chest and abdomen as well as regular dependence on blood transfusion compared to SCD with the wild type. Age- and sex-adjusted logistic regression analysis revealed a significant association between FVL and sickle cell anemia with an odds ratio (OR) of 5.6 (95% confidence intervals [CI] of 1.91–39.4, P = 0.039) in SS patients. However, increased prevalence of the FVL in AS subjects and sickle β-thalassemia patients was not statistically significant compared to controls (OR 3.97, 95% CI 0.51–28.6, P = 0.17 and OR 3.59, 95% CI 0.35–41.6, P = 0.26, respectively). The distribution of prothrombin G20210A mutation among SCD patients compared to controls was not significantly different, thus our findings do not support an association of this mutation with SCD.

Conclusions

FVL was more prevalent among SS patients compared to controls and it was associated with higher incidence of disease complications among SCD patients.

Coagulation, thrombophilia and patency of arteriovenous fistula in children undergoing haemodialysis compared with healthy volunteers: a prospective analysis

This study aimed to assess whether markers of coagulation, fibrinolysis or thrombophilia are increased in children on haemodialysis compared with controls and whether measurement of any of these factors could help to identify patients at an increased risk of arteriovenous fistula (AVF) occlusion. Blood samples were taken from 55 children immediately before a session of haemodialysis and from 20 healthy volunteers. Thrombin-antithrombin (TAT), D-dimer, plasmin-antiplasmin (PAP) and anticardiolipin immunoglobulin G (ACA-Ig G) were measured by ELISA. Factor V Leiden mutation (G1691A) was determined by gene polymorphism [restriction fragment length polymorphism (RFLP)]. Determination of the patency of the AVF was prospectively followed up for a minimum of 4 years or until the AVF was nonfunctioning. Fifty-five patients were studied with a median follow-up of 659 days (range 30-1670 days). A significant increase was found in the levels of D-dimer, PAP and ACA-Ig G in haemodialysis patients with thrombosed and nonthrombosed native AVFs vs.

CONTROLS

There was a significant difference between both chronic haemodialysis patients with thrombosed and nonthrombosed native AVF with regard to ACA-IgG levels. At 1 year follow-up, primary patency was 61.4% (27 patients). In multivariate analysis, D-dimer was inversely associated with secondary patency.Thrombophilia may predispose children with end stage renal disease to access failure. The promising finding is that in children on haemodialysis, D-dimer levels were increased and inversely correlated with secondary patency. Further evaluation is required into the possible role of D-dimer as a biomarker of AVF occlusion.

Genetic Risk Factors of Venous Thromboembolism in the East Algerian Population

Many genetic risk factors have been identified for causing venous thromboembolism (VTE). Most of them affect the function of natural anticoagulant pathways, particularly the protein C system, although recent studies suggest a role of components of the hematopoietic pathway in the etiology of venous thrombosis. In this case–control study, we aimed to determine the frequency of prothrombin G20210A and factor V Leiden (FVL) G1691A polymorphisms and protein C, protein S, and antithrombin III deficiencies in the East Algerian population and to investigate whether these genetic factors are associated with VTE. On the other hand, our study tends to evaluate the status of JAK2V617F and calreticulin (CALR) mutations among these cases. The participants consisted of 121 cases with VTE and 146 healthy controls. Polymorphisms of FVL G1691A and prothrombin G20210A were genotyped by polymerase chain reaction (PCR) restriction fragment length polymorphism. JAK2-V617F and calreticulin mutations were analyzed by quantitative PCR and PCR followed by capillary electrophoresis sequencing, respectively. Protein C, protein S, and antithrombin levels were determined and then hereditary deficiencies were identified. Of all cases and controls, none was a carrier of the antithrombin III deficiency, prothrombin gene G20210A, and CALR mutations. Only 1 case reported having a positive JAK2 mutation (mutant allele burden was 15%). The FVL mutation (GA/AA) was found in 14 (11.6%) cases and 2 (1.4%) controls and it was significantly different between both the groups ( P = .001). Deficiencies of protein S and protein C were detected in 17 (18.8%) cases. The univariate analysis resulted in a significant impact of FVL (odds ratio [OR] = 9.4, 95% confidence interval [CI] = 2.1-42.3; P = .003) and of protein S deficiency (OR = 16.9, 95% CI =2.1-132.8, P = .007) on the VTE status. Both factors stayed significant after adjustment for sex and age. The OR of the protein C deficiency was slightly elevated (OR = 6.4, 95% CI = 0.7-55.5), but it did not reach the level of statistical significance ( P = .091), and it was therefore not considered as a risk factor. In conclusion, coagulant factor V gene G1691A mutation and protein S deficiency constitute important genetic risk factors in patients with VTE in Eastern Algeria. The somatic mutation of JAK2 V617F and CALR mutations are less frequent causes of VTE, thus routine testing for these mutations is not recommended.

Activated Protein C-Resistance Determination and Vascular Access Thrombosis in Populations with High Prevalence of Factor V Leiden

BACKGROUND/AIMS

Factor V Leiden heterozygosity occurs in 3-8% of the general European and US populations. Activated protein C resistance (APC-R)--a non-molecular laboratory test--can efficiently demonstrate the presence of this mutation and can be performed on most coagulation analyzers. On the other hand, fistula or graft thrombosis is a common and costly complication in hemodialysis patients. Our aim was to establish the value of APC-R determination in hemodialysis patients by assessing the risk of access thrombosis in patients with increased APC-R.

METHODS

A total of 133 patients (81 men, mean age 64.5 ± 14.9 years and 52 women, mean age 63.6 ± 15 years) were selected. Participants were divided into 2 groups: those with access thrombosis (54 patients, 40.6%) and those with no access thrombosis (79 patients, 59.4%), and they were tested for the most common congenital or acquired thrombophilia risk factors.

RESULTS

Overall, 12 patients (9%) had an increased APC-R and 10 of them had at least 1 episode of access thrombosis (83.3%). Univariate analysis to estimate crude odds ratio (OR) showed an OR of 8.8 (95% CI 1.8-41.8) times higher risk for access thrombosis in these patients. No significant differences were found after adjusting for age, hypertension, diabetes mellitus, coronary artery disease, cerebrovascular disease, peripheral arterial disease and malignancy. Sex was also a factor influencing thrombosis, presenting a higher OR for women (OR 2.2, 95% CI 1.1-4.4).

CONCLUSION

This study revealed a significant association between access thrombosis and increased APC-R in hemodialysis patients. This indicates that the determination of APC-R should be considered--especially, in populations with a high prevalence of Factor V Leiden--as proper anticoagulant therapy in these patients may reduce the risk of access thrombosis.

Ethnic diversity in the genetics of venous thromboembolism

Genetic susceptibility is considered as a crucial factor for the development of venous thromboembolism (VTE). Epidemiologic and genetic studies have revealed clear disparities in the incidence of VTE and the distribution of genetic factors for VTE in populations stratified by ethnicity worldwide. While gain-of-function polymorphisms in the procoagulant genes are common inherited factors in European-origin populations, the most prevalent molecular basis for venous thrombosis in Asians is confirmed to be dysfunctional variants in the anticoagulant genes. With the breakthrough of genomic technologies, a set of novel common alleles and rare mutations associated with VTE have also been identified, in different ethnic groups. Several putative pathways contributing to the pathogenesis of thrombophilia in populations of African-ancestry are largely unknown, as current knowledge of hereditary and acquired risk factors do not fully explain the highest risk of VTE in Black groups. In-depth studies across diverse ethnic populations are needed to unravel the whole genetics of VTE, which will help developing individual risk prediction models and strategies to minimise VTE in all populations.

Polymorphisms in Factor II and Factor V thrombophilia genes among Circassians in Jordan

Thrombosis is a major cause of morbidity and mortality worldwide. Genetic factors are one component of thrombosis. We studied the prevalence of two mutations that are known risk factors in the pathogenesis of arterial and venous thrombosis in the genetically isolated Circassian population in Jordan. Factor II G20210A and Factor V Leiden single nucleotide polymorphisms were analysed by polymerase chain reaction and restriction fragment length polymorphism method in 104 random unrelated subjects from the Circassian population in Jordan. The prevalence rates among the Circassian population in Jordan for Factor II G20210A was 12.2% and for Factor V Leiden was 7.7%. We have shown that the population is in Hardy-Weinberg equilibrium and that the prevalences of both mutations are within the range of other ethnic groups. This is the first study to describe Circassian health related genetic characteristics in Jordan. Such population-based studies will contribute to understanding the interaction between genetic and environmental risk factors. It will remain to be seen whether carriers of Factor II G20210A and Factor V Leiden are more likely to develop thrombosis. This issue should be studied in the future to determine the need for screening of these mutations particularly in thrombophilia patients.

Thrombophilic gene polymorphism studies in G6PD deficient individuals from Saudi population

We performed a study to evaluate the role of three single nucleotide polymorphisms (SNPs), factor V Leiden G1691A (FVL), prothrombin gene mutation G20210A (PRT or FII-G20210A) and methylenotetrahydrofolate reductase variant C677T (MTHFRC677T), as risk factors for G6PD in Saudi populations. Our results did not show any association with the three Thrombophilic genes with FVL gene, no statistical analysis have shown any association with either allele or genotype frequencies OR=0.566, p=.0.667, (95% CI=0.014-22.48) and OR=0.569, p=0.251¸ (95% CI=0.014-22.96).In PRT gene G20210A for G Vs A, p=0.774; OR=0.566 (95%CI; 0.011-29.6); AA+GA Vs GG; p=0.502; OR=0.569 (95%CI=0.010-2969). G and A allele frequencies were similar between cases and controls with no statistical significance. In the MTHFR gene none of the genotypes or allele frequency cannot show any association OR=1.281, p=.0.667, (95% CI=0.414-3.958) and OR=1.1.172, p=0.800¸ (95% CI=0.343-4.008). Similarly, the difference of T allele frequencies between patients and controls was not found any association. In conclusion, our finding indicates that the prevalence of G1691A, G20210A and C677T mutations in G6PD deficient individuals is not statistically different compared to normal subjects and G6PD is not associated with these thrombophilic mutations in Saudi population.

Factor V Leiden, prothrombin 20210G>A, MTHFR 677C>T and 1298A>C, and homocysteinemia in Tunisian blood donors

Specific genetic conditions are known to be associated with high risk of venous thromboembolism. This genetic basis varies widely between ethnic groups. We investigated the distribution of four inherited polymorphisms in 113 unselected Tunisian blood donors by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The allele frequencies of Factor V Leiden (FVL), prothrombin 20210G>A, methylenetetrahydrofolate reductase (MTHFR) 677C>T, and MTHFR 1298A>C mutations were 3, 0.9, 30, and 31%, respectively. The MTHFR 677C>T polymorphism was influenced by age. Twenty-nine of the 113 blood donors demonstrated more than one genetic markers. Hyperhomocysteinemia was found in 12 subjects, and it was statistically associated to the MTHFR 677TT genotype. Principal component analysis allowed disclosing the resemblance between Mediterranean populations. Our findings may be helpful for population genetics study, and provide epidemiologic database for further studies in thrombosis field among Tunisians.

Contribution of JAK2 and STAT3 variants to the genetic susceptibility of recurrent spontaneous miscarriage in a Tunisian population

AIMS

Th1 and Th2 balance is crucial for maintenance of pregnancy, and intracellular JAK and STAT proteins significantly contribute to it. In view of evidence linking JAK2 and STAT3 variants with recurrent spontaneous miscarriage (RSM), here we investigated the association of JAK2 (rs2230724) and STAT3 (rs1053023 and rs1053004) to RSM susceptibility in Tunisians.

SUBJECTS AND METHODS

A retrospective case-control study. Subjects comprised 235 RSM cases and 235 control subjects. JAK2 and STAT3 were genotyped by the allelic discrimination method.

RESULTS

STAT3 rs1053023 and, to a lower extent, rs1053004 were significantly associated with RSM under the additive and dominant, but not recessive models. This remained significant after adjustment for the covariates age, smoking, and gravida. In contrast to STAT3 variants, JAK2 rs2230724 was not associated with RSM under any of the genetic models tested. Two-locus STAT3 (rs1053023/rs1053004) haplotype analysis revealed increased frequency of the C/G haplotype in patients with RSM. Multivariate regression analysis confirmed the association of C/G haplotype with RSM (p=0.001; odds ratio=2.01; 95% confidence interval=1.32-3.07), thus conferring RSM susceptibility nature. These differences remained significant after applying the Bonferroni correction for multiple testing (Pc=0.004).

CONCLUSIONS

STAT3 rs1053023, more so than the STAT3 rs1053004 or JAK2 rs2230724 polymorphisms, is associated with RSM risk.

Epidemiology of Prothrombin G20210A Mutation in the Mediterranean Region

There are many genetic and acquired risk factors that are known to cause venous thromboembolic disorders (VTE). One of these is the Prothrombin G20210A mutation, which has been identified in 1996. Prothrombin G20210A mutation causes higher levels of the clotting factor prothrombin in the blood of carriers, which creates a higher tendency towards blood clotting (hypercoagulability), and therefore the carriers become at higher risk of developing VTE. High prevalence of Prothrombin G20210A mutation was reported in Caucasian populations, but the prevalence was almost absent in non-Caucasians. That was most obvious in countries of South Europe and the Mediterranean region. This review article discusses Prothrombin G20210A mutation, how it causes VTE, the origin of the mutation, and its distribution worldwide with special concentration on the Mediterranean area.

Prevalence of factor V Leiden in south Tunisian blood donors

Venous thrombosis (VT) is a common disease with multifactorial pathogenesis. Factor V Leiden mutation (G1691A) (FVL) is the most common risk factor in venous thrombosis. The prevalence of FVL varies according to geography and ethnicity. Hence, in several countries there is a difference in the frequency of this mutation between the southern, central and north. In Tunisia, no data is available about prevalence of FVL mutation by geographical origin. For this reason, we sought the prevalence of FVL mutation in blood donor of south Tunisia population. FVL has been detected by APCR-test and confirmed by PCR-RFLP and sequencing. Two hundred fifty blood donors, different in age and sex were included in this study to determine the prevalence of FVL in blood donors. FVL mutation was found in 13.6% of the studied population. Thirty-one were heterozygous and three persons were homozygous with a rate of 12.4 and 1.2%, respectively. In conclusion, FVL mutation is very common in south Tunisian population.

Epidemiology of activated protein C resistance and factor v leiden mutation in the mediterranean region

Venous thromboembolic disorders (VTE) are serious disorders with high morbidity and mortality rates. Many genetic and acquired risk factors were identified to cause VTE. The most common genetic risk factor is Factor V Leiden mutation (FVL). FVL was found in high percentage of populations of Caucasian origin but was almost absent in non-Caucasians. It was also reported in populations living in North Africa and the Middle East. This review article briefly explains FVL and how it causes VTE, the distribution of FVL worldwide, and then it elaborates on the epidemiology of FVL in the Mediterranean Region and how this brought speculations that FVL might have originated in the Eastern Mediterranean area.

Association of inherited thrombophilia with recurrent pregnancy loss in palestinian women

Objective. This study aimed at analyzing the association between recurrent pregnancy loss (RPL) and factor V G1691A (FVL), prothrombin G20210 (FII); and MTHFR C677T (MTHFR) in Palestinian women. Method. We studied 329 Palestinian women with RPL and/or stillbirth (SB); and compared them to 402 healthy reproductive Palestinian women. Cases and controls were tested for the above mutations. Odds ratio (OR) at confidence interval (CI) of 95% was used as a measure of association between the mutations and RPL. Results. Our statistical analysis showed a slightly increased association, which was not significant between FVL and RPL (OR 1.32, 95% CI 0.90-1.94), and no association between FII (OR 0.84, 95% CI 0.38-1.92), MTHFR (OR 0.58, 95% CI 0.32-1.03), and RPL. Further analysis of RPL subgroups revealed an association between FVL and first-trimester loss (OR 1.33, 95% CI 0.892-1.989), and second-trimester loss (OR 1.13, 95% CI 0.480-2.426), both were not statistically significant. Furthermore, the only statistically significant association was between FVL and SB (OR 2.0, 95% CI 1.05-3.70). Conclusion. Our analysis had failed to find a significant association between FVL, FII, MTHFR; and RPL in either the first or second trimester. FVL was significantly associated with fetal loss if the loss was a stillbirth.

Race differences in the prevalence of the factor V Leiden mutation in Kuwaiti nationals

Factor V Leiden mutation (FVL; G1691A) is an established risk factor for venous thromboembolic disorders. FVL was reported with high prevalence in Caucasians (1-15%) but was absent in non-Caucasians like Africans and Asians. Studies reported FVL in 5-27% of Arabs and non-Arabs living in the Middle Eastern countries northern to the Arabian Peninsula, but was almost absent in Arabs in the Arabian Peninsula itself. Kuwait is an Arabic country present on the northern border of the Arabian Peninsula, and Kuwaitis are originally from Saudi Arabia (Southern to Kuwait and within the Arabian Peninsula) or from Iran and Iraq (northern to Kuwait and the Arabian Peninsula). This study was conducted to study FVL in Kuwaitis in relation to their origin. Real-time PCR was performed on DNA samples of 285 apparently healthy Kuwaitis using specially designed primers and probes for FVL. There were 109 Kuwaitis of Iranian origin, 71 of Iraqi origin and 105 of Saudi origin. FVL was present in 7 and 5 Kuwaitis of Iranian and Iraqi origin, respectively. None of the Kuwaitis of Saudi origin had the mutation. Prevalence of FVL in Kuwaitis of Iranian (6.42%) and Iraqi (7.04%) origin were statistically different from prevalence in Kuwaitis of Saudi (0%) origin (P-value<0.05). No difference was found between females and males (P-value>0.6). In conclusion, FVL is present in Kuwaitis of Iranian or Iraqi origin only. Therefore, testing and providing genetic consultation for FVL may be needed in those Kuwaitis only which should save time, cost and efforts. However, this assumption should be confirmed by other studies and on larger number of cases.

HLA sharing among couples appears unrelated to idiopathic recurrent fetal loss in Saudi Arabia

BACKGROUND

Recurrent fetal loss (RFL) is a prevalent problem affecting approximately 1% of all women of childbearing age. Many factors can lead to RFL; however, recent studies have indicated the important role of the maternal immune system in this process. The human leukocyte antigens (HLA), HLA-linked genes and regulatory factors play an important role in fetal loss and in fetal development. The current retrospective study was preformed to examine the HLA alleles shared between couples with RFL in Saudi Arabia, using a large cohort of women (having three or more RFL). Specific HLA alleles that could influence this condition, or the number of miscarriages experienced, were expected to be highlighted in this way.

METHODS

A total of 253 consecutive patients who visited the RFL clinic at the King AbdulAziz Medical City, National Guard Hospital in Riyadh were included in this study. They included 54 consanguineous couples, 132 non-consanguineous couples and another 67 couples shared only their tribal origin. Clinical examinations as well as laboratory investigations were carried out on each patient. Class I HLA, HLA-A, HLA-B and HLA-C, and Class II HLA, HLA-DR and HLA-DQ, were typed for each patient and their partner.

RESULTS

No relationship was seen between sharing of HLA alleles and the number of RFL experienced by the couples, among neither consanguineous nor non-consanguineous couples.

CONCLUSIONS

Although the results of this study suggest that HLA sharing is not an indicative factor in RFL, definitive conclusions on this topic must be based on large case-control studies.

Prevalence of factor V Leiden (G1691A) and prothrombin (G20210A) among Kurdish population from Western Iran

BACKGROUND

The mutation in factor V (FV) G1691A, known as factor V Leiden, and prothrombin (FII) gene G20210A are the two most prevalent causes of inherited thrombophilia. The present study reports the prevalence of factor V Leiden and the prothrombin G20210A gene mutations among healthy individuals of Kurdish ethnic background in Western Iran.

METHODS

Four hundred thirty-four healthy unrelated individuals, 255 male and 179 female, with a mean age of 28.7+/-15.5 from the Kermanshah Province of Iran were studied for prothrombin G20210A mutation. The factor V Leiden mutation was studied in 404 healthy individuals, of whom 232 were male and 172 were female. The factor V Leiden and prothrombin G20210A were detected by polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method using Mnl I and Hind III restriction enzymes, respectively.

RESULTS

Among 434 individuals studied for prothrombin G20210A mutation seven carried this mutation as heterozygous (four female subjects and three male), giving a prevalence of 1.6% [95% confidence intervals (CI) 0.5-2.7) and an allele frequency of 0.8%. No homozygous prothrombin 20210AA was found. Factor V G1691A mutation was detected as heterozygous in 11 of 404 healthy individuals (five female and six male) and as homozygous in one male indicating a prevalence of 2.97% (95% CI 1.3-4.6) and allele frequency of 1.6%.

CONCLUSIONS

Our results indicated that the factor V Leiden and prothrombin G20210A mutations are not rare among populations of Western Iran and that the relationship between venous thrombophilia and these mutations have to be further studied in Western Iran population, which, in turn, may suggest a causal effect.

Thrombophilic mutations among Southern Iranian patients with sickle cell disease: high prevalence of factor V Leiden

BACKGROUND

A hypercoagulable state in sickle cell disease (SCD) and beta thalassemia has been established and thrombosis is an important aspect of the clinical spectrum of sickle cell disease. In a case-control study, the prevalence of factor V Leiden and prothrombin G20210A mutations were investigated among SCD patients from Southern Iran.

METHODS

Patients comprised 60 individuals with SCD; of them 35 were with sickle cell anemia (SS) including 21 males and 14 females aged 17.2+/-8.3 years, 15 were sickle cell trait (AS) consisted of nine males and six females aged 30+/-15.4 years and 10 were sickle/beta thalassemia (S/Thal) (three males and seven females) aged 24.6+/-10.4 years. The control group were 126 apparently healthy individuals (50 males and 76 females) aged 20.1+/-9.8 years. Genotyping was done by polymerase chain reaction restriction fragment-length polymorphism (PCR-RFLP) using Mnl I and Hind III for factor V Leiden and prothrombin G20210A, respectively.

RESULTS

Heterozygous factor V Leiden mutation was found in five of 35 (14.3%) SS patients, two of 15 (13.3%) AS individuals, one (a sickle/beta-zero thalassemia patient with IVSII.1 G-->A mutation) of 10 S/Thal patients (10%), and two of 126 (1.6%) control subjects (P<0.05). However, only one AS individual (6.7%) was found to be a carrier for prothrombin G20210A compared to five of 126 (4%) healthy individuals. Adjusted logistic regression analysis for the effects of age and sex was performed and a significant association was found between factor V Leiden mutation and sickle cell anemia with odds ratios (OR) of 6.5 (95% confidence intervals [CI] 1.19-35.33, P=0.03) in SS patients. However, increased prevalence of the factor V Leiden in AS individuals and S/Thal patients was not statistically significant compared to controls (OR 3.84, 95% CI 0.49-29.9, P=0.19 and OR 3.77, 95% CI 0.31-45.9, P=0.29, respectively).

CONCLUSIONS

Our findings indicate a significant correlation between factor V Leiden and sickle cell anemia among Iranian patients. Association between venous thrombophilia and factor V Leiden mutation in Iranians with sickle cell anemia should be further studied.

Distinct association of factor V-Leiden and prothrombin G20210A mutations with deep venous thrombosis in Tunisia and Lebanon

Factor V G1691A (FV-Leiden) and prothrombin (PRT) G20210A single nucleotide polymorphisms (SNPs) were associated with venous thrombosis among Caucasians. We assessed the contribution of both SNPs to the genetic susceptibility of deep venous thrombosis (DVT) among Lebanese and Tunisian patients. Subjects comprised 198 DVT patients and 540 healthy controls from Lebanon and 126 Tunisian DVT patients and 197 control subjects; FV-Leiden (MnlI) and PRT G20210A (HindIII) genotyping was done by PCR-RFLP. While the prevalence of FV-Leiden mutant A allele and the G/A and A/A genotypes were significantly higher among DVT patients from Lebanon and Tunisia, the association of PRT G20210A with DVT was pronounced among Lebanese but not Tunisian patients. The prevalence of PRT G20210A mutant A allele (P < 0.001 vs. P = 181) and G/A genotype (P < 0.001 vs. P = 0.994) was significantly higher among Lebanese but not Tunisians, respectively. While FV-Leiden was a common genetic risk factor for DVT in both communities, the contribution of PRT G20210A to the genetic susceptibility of DVT differed among Lebanese and Tunisians, which underscores the need to determine prothrombotic gene polymorphisms associated with DVT among Arab and Mediterranean basin communities.