Superficial venous thrombosis: prevalence of common genetic risk factors and their role on spreading to deep veins.
BACKGROUND
Superficial venous thrombosis (SVT) has been considered for a long time a limited clinical condition with a low importance, but this approach has changed in recent years, when several studies demonstrated spreading to deep veins occurring from 7.3 to 44%, with high prevalence of pulmonary embolism.


METHODS
To evaluate the prevalence of genetic risk factors for VTE in patients suffering from SVT on both normal and varicose vein, and to understand their role on spreading to deep veins, we studied 107 patients with SVT, without other risk factors. Ultrasound examination was performed, and the presence of FV Leiden, Prothrombin G20210A mutation, and MTHFR C677T mutation was researched.


RESULTS
In the patients where SVT occurred in normal veins, the presence of FV Leiden was 26.3% of the non-spreading and 60% of the spreading to deep veins SVT; Prothrombin mutation was found in 7.9% of the former case and in 20% of the latter; MTHFR C677T mutation was found respectively in 23.7% and 40%. In the patients with SVT on varicose veins, the presence of these factors was less evident (6.7%, 4.4% and 6.7% respectively), but their prevalence was considerably higher (35.7%, 7.4% and 21.4% respectively) in SVT spreading to deep veins than in non-spreading.


CONCLUSIONS
Our data demonstrate the high prevalence of these mutations, especially FV Leiden and associations, in patients with SVT on normal veins and their role in the progression to deep vein system.
Milio
Glauco
G
University of Palermo - Department of Internal Medicine, Cardiovascular and Nephrourological Diseases, Italy. glaucomilio@libero.it
Siragusa
Sergio
S
Minà
Chiara
C
Amato
Corrado
C
Corrado
Egle
E
Grimaudo
Stefania
S
Novo
Salvatore
S
D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D005165:Factor V / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D008875:Middle Aged; D009154:Mutation; D010689:Phlebitis / Q000150:complications; D015995:Prevalence; D011516:Prothrombin / Q000235:genetics; D011655:Pulmonary Embolism / Q000150:complications / Q000453:epidemiology / Q000235:genetics; D012307:Risk Factors; D014648:Varicose Veins / Q000453:epidemiology / Q000209:etiology / Q000235:genetics; D014680:Veins; D020246:Venous Thrombosis / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics*; D055815:Young Adult
C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin; D042965:Methylenetetrahydrofolate Reductase (NADPH2)