title: Primary thrombophilia in Mexico. II. Factor V G1691A (Leiden), prothrombin G20210A, and methylenetetrahydrofolate reductase C677T polymorphism in thrombophilic Mexican mestizos.
abstract: We have shown that in Mexican mestizo patients with clinical features of primary thrombophilia, 39% have activated protein C resistance phenotype, 5% protein C deficiency, and 2% protein S deficiency. In the present study, in a group of 37 thrombophilic Mexicans and 50 normal controls, we assessed the factor V G1691A (Leiden), the prothrombin G20210A, and the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms. Four patients were found to be heterozygous for factor V Leiden, 5 heterozygous for the prothrombin 20210, 16 heterozygous, and 6 homozygous for the MTHFR 677. There were four individuals with co-segregation of alleles: two heterozygotes for the factor V Leiden/prothrombin 20210, one heterozygote for prothrombin 20210/MTHFR 677, and one heterozygote for prothrombin 20210/homozygote for MTHFR 677. For factor V Leiden, prothrombin 20210, and MTHFR 677 mutations, the allele frequencies were respectively 1% (+/-0.2%, alpha = 0.05), <1% and 51% (+/-5%, alpha = 0.05), with calculated relative risks for thrombosis of 5.94 (P = 0.08), >7.66 (P < 0.05), and 0.44 (P NS), respectively. In Mexican mestizo thrombophilic patients, the low prevalence of the factor V Leiden mutation (10.8%) and the high prevalence of the prothrombin 20210 mutation (13.5%) contrast with those identified in Caucasian thrombophilic patients (21% and 6%, respectively; P < 0.01). On the other hand, the high prevalence of the MTHFR 677 mutation gene both in normal controls (78%) and thrombophilic patients (61%) does not support a role of this mutation in the thrombogenesis of Mexican mestizo patients.
authors: Centro de Hematología y Medicina Interna de Puebla, Mexico. gruiz1@prodigy.net.mix
authors: G J
authors: GJ
authors: Ruiz-Argüelles
authors: J
authors: J
authors: Garcés-Eisele
authors: V
authors: V
authors: Reyes-Núñez
authors: F J
authors: FJ
authors: Ramírez-Cisneros
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D020016:Activated Protein C Resistance / Q000453:epidemiology* / Q000208:ethnology / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000483:Alleles; D019943:Amino Acid Substitution; D044383:Black People / Q000235:genetics; D002648:Child; D005165:Factor V / Q000032:analysis*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007198:Indians, North American / Q000235:genetics; D008297:Male; D008393:Marriage; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D017354:Point Mutation; D015995:Prevalence; D011446:Prospective Studies; D011516:Prothrombin / Q000235:genetics*; D019851:Thrombophilia / Q000453:epidemiology* / Q000208:ethnology / Q000235:genetics; D044465:White People / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)