Thrombosis SNP FV Leiden FII G20210A Total Total Total MTHFR C677T Table 2: Genotype frequency of thrombophilias. Genotype GG (normal) GA AA GG (normal) GA AA CC (normal) CT TT Cases, n (%) 92 (98.9%) 1 (1.1%) 0 93 (100%) 92 (98.9%) 1 (1.1%) 0 93 (100%) 38 (40.9%) 43 (46.2%) 12 (12.9%) 93 (100%) Controls, n (%) 205 (99.5%) 1 (0.5%) 0 206 (100%) 205 (99.5%) 1 (0.5%) 0 206 (100%) 93 (45.1%) 83 (40%) 30 (14.9%) 206 (100%) Controls, n (%) 2 (1%) 3 (1.5%) 8 (4.3%) 1 (12.5%) 7 (87.5%) 3 OR (CI 95%) 0.4 (0–16.44) 2.2 (0–83) ND 0.4 (0–16.4) 2.2 (0–83) ND 0.8 (0.5–1.4) 1.3 (0.8–2.1) 0.8 (0.4–1.8) OR (CI 95%)∗ 0 (0–9.2) 1.44 (0.2–10.8) 1.36 (0.4–4.8) 1.75 (0–93) SNP: single nucleotide polymorphism; n: number of women; OR: odds ratio; CI 95%: Cornﬁeld’s 95% conﬁdence interval for the OR; ND: not determined (0% frequency); FV: factor V; FII: prothrombin; MTHFR: methylenetetrahydrofolate reductase. Table 3: Frequency of antithrombin deﬁciency, protein C deﬁciency, and activated protein C resistance. Alteration AT deﬁciency (<50%) PC deﬁciency (<50%) APC resistance APC resistance with FV Leiden APC resistance without FV Leiden Cases, n (%) 0 2 (2.2%) 5 (5.7%) 1 (20%) 4 (80%) n: number of women; OR: odds ratio; CI 95%: Cornﬁeld’s 95% conﬁdence interval for the OR; AT: antithrombin; PC: protein C; APC: activated protein C. N/A: not applicable. functional phenotypes (APC resistance, PC deﬁciency, and AT deﬁciency). 4. Discussion The present study is the ﬁrst to report the frequency of inher- ited thrombophilia (thrombophilic polymorphisms and functional tests) in a group of Colombian patients with recurrent pregnancy loss. Thrombophilia-associated SNPs such FV Leiden and FII G20210A were very low in both patients and controls, and although the frequency of MTHFR C677T SNPs was high in the patients, diﬀerences were not signiﬁcant. Other inherited thrombophilias such as PC and AT deﬁciency are not commonly found in patients who had already experienced recurrent pregnancy loss. Only three patients with PC deﬁciency and no patients with AT deﬁciency were found among 93 cases. Overall, we found a low frequency of inherited thrombophilia in our patient population unlike Caucasian populations; therefore, it is un- likely that the thrombophilic alterations studied play a role in the pathogenesis of recurrent pregnancy loss in this Latin American population. The low frequency of FV Leiden in our study agrees with two previous reports on the Colombian population. Cama- cho Vanegas et al. tested 150 healthy individuals from Bogota (30–50 years old) using PCR-RFLP and found no evidence of FV Leiden [35]; however, the allelic frequency of the MTHFR C677T SNP was 0.487, one of highest reported in the liter- ature (70/150 heterozygous CT and 38/150 homozygous TT) [35]. The other study was performed by Varela et al. and used PCR-sequence speciﬁc oligonucleotide probes in 495 Colombian blood donors from banks in four cities, reporting a prevalence of FV Leiden of 1.9% (7/370) in indi- viduals from Bogota, while it was 0% in 125 individuals from the other three cities (Medell´ın, Bucaramanga, and Bar- ranquilla) [36]. In addition, the presence of inherited throm- bophilia in 100 Colombian patients with deep venous throm- bosis and in a control group (n = 114) was evaluated with the following results in patients versus controls: 10% versus 0.9% were heterozygous for FV Leiden, 3% versus 0% were heterozygous for FII G20210A (one patient was homozy- gous), 24% versus 19.3% were homozygous for MTHFR 677T, and 25.2% versus 5.3% had APC resistance (these thrombophilias reached statistical signiﬁcance, except for the MTHFR polymorphisms) [37]. During this research, the ﬁrst homozygous family for the G20210A prothrombin polymorphism reported in Latin America, although only some carriers developed venous thrombosis [38]. The FV Leiden, as genetic factor involved in the etiology of thrombosis, has motivated research of this abnormality as a risk factor for recurrent pregnancy loss, as reviewed by Krabbendam et al. [39]; however, this association has not been easy to conﬁrm in multiple studies, making it necessary to reevaluate the experimental design and population size. For example, Nurk et al. [40] evaluated FV Leiden in