Factor V R506Q mutation-Leiden: an independent risk factor for venous thrombosis but not coronary artery disease.
BACKGROUND
A specific point G-A transition at nucleotide position 1691 in the factor V (FV) gene, FV-Leiden, was associated with increased risk of venous thromboembolism (VTE). Insofar as the association of FV-Leiden with coronary artery disease (CAD) remains poorly defined, the aim of this study was to determine the prevalence of FV-Leiden in a sample of 68 VTE patients, 69 CAD patients, and 192 randomly selected healthy subjects.


METHODS
Total genomic DNA was extracted from the peripheral blood of study subjects and was used for PCR analysis. The presence (or absence) of FV-Leiden was assessed by PCR using primers flanking the mutant site (nt 1691), followed by hybridization with wild-type ('G') and mutant ('A') biotinylated DNA probes; detection was by DNA enzyme immunoassay (DEIA).


RESULTS
While the prevalence of FV-Leiden in CAD patients was not statistically different from that of healthy subjects (14.5 % vs. 15.1 %; P=0.890, odds ratio 0.95; 95 % confidence interval 0.43--2.06), a significant increase in FV-Leiden prevalence was seen in VTE patients (70.6 % in VTE patients; P<0.001, odds ratio 13.4, 95 % confidence interval 6.9--25.8). Of the 48 VTE patients who tested positive for FV-Leiden, 42 were heterozygotes (G/A), while 6 were homozygotes (A/A) (allele frequency 0.397). All 10 CAD patients positive for FV-Leiden were heterozygote carriers (allele frequency 0.072). While gender was not a factor in FV-Leiden expression, higher prevalence in FV-Leiden was seen in younger (< or =45 years) VTE patients (38/51 vs. 10/17).


CONCLUSIONS
FV-Leiden is a major inherited risk factor for VTE, with a peak incidence in younger patients, but does not appear to play any role in CAD pathogenesis in the population studied.
Irani-Hakime
N
N
Department of Laboratory Medicine, St. Georges-Orthodox Hospital, Beirut, Lebanon.
Tamim
H
H
Elias
G
G
Choueiry
S
S
Kreidy
R
R
Daccache
J L
JL
Almawi
W Y
WY
D020016:Activated Protein C Resistance / Q000150:complications* / Q000235:genetics; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003327:Coronary Disease / Q000453:epidemiology* / Q000235:genetics; D005165:Factor V / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007861:Lebanon / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors; D019851:Thrombophilia / Q000235:genetics*; D020246:Venous Thrombosis / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics
C095381:factor V Leiden; D005165:Factor V