Role of the M2 haplotype within the annexin A5 gene in the occurrence of pregnancy-related venous thromboembolism.
OBJECTIVE
Knowledge about risk factors for venous thromboembolism (VTE) is still limited. A recently found haplotype within the natural anticoagulant protein annexin A5 (ANXA5) exerts an important modulating effect on gene expression.


METHODS
Eighty-three nonanticoagulated patients with a documented pregnancy-related VTE and 195 controls were investigated. The presence of the ANXA5 haplotypes was determined.


RESULTS
Twenty-seven patients (32.5%) carried the M2 haplotype. Among them, 17 (63.0%) had a history of VTE in puerperium and 10 (37.0%) during pregnancy. The prevalence of the M2 haplotype was different as compared with that recorded among controls (odds ratio, 2.7; 95% confidence interval, 1.5-4.9, P < .001). A logistic regression analysis, correcting for potential confounders (age at which the thrombotic event occurred, factor V Leiden, and factor IIA20210 variants) showed a significant increase (odds ratio, 3.4; 95% confidence interval, 1.7-6.7) of the occurrence of VTE in carriers of the M2 haplotype as compared with noncarriers.


CONCLUSIONS
The M2 haplotype within the ANXA5 gene may represent a new thrombophilic risk factor for pregnancy-related VTE.
Grandone
Elvira
E
Atherosclerosis and Thrombosis Unit, Research Department, Istituto di Ricovero e Cura a Carattere Scientifico, Casa Sollievo della Sofferenza, S. Giovanni Rotondo, Foggia, Italy. e.grandone@operapadrepio.it
Tiscia
Giovanni
G
Colaizzo
Donatella
D
Chinni
Elena
E
Pisanelli
Daniela
D
Bafunno
Valeria
V
Margaglione
Maurizio
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D017304:Annexin A5 / Q000235:genetics*; D005165:Factor V / Q000235:genetics; D005260:Female; D056726:Genetic Association Studies; D006239:Haplotypes; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D016017:Odds Ratio; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000235:genetics*; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000235:genetics*
D017304:Annexin A5; D005165:Factor V