Racial differences in protein S Tokushima and two protein C variants as genetic risk factors for venous thromboembolism
Hiroko Tsuda, Kenta Noguchi, Doyeun Oh, Zsuzsanna Bereczky, Lai H. Lee, Dongchon Kang, Luci Maria Sant’Ana Dusse, María das Graças Carvalho Ferriani, Eriko Morishita
Abstract
BACKGROUND: Racial differences in genetic risk factors for venous thromboembolism (VTE) are elucidated, with factor V Leiden and prothrombin G20210A being prevalent among the Caucasian population but rare among non-Caucasians. OBJECTIVES: To assess the worldwide distribution of three gene polymorphisms previously identified as genetic risk factors among East Asian subpopulations: protein S (PS) Tokushima (p.Lys196Glu), protein C (PC) p.Arg189Trp, and PC p.Lys193del. METHODS: An international collaborative study group of seven centers in five countries-Japan, South Korea, Singapore, Hungary, and Brazil-was created, and genotype analyses were performed. A total of 2850 unrelated individuals (1061 patients with VTE and 1789 controls) were included. RESULTS: PS Tokushima was confined to Japanese patients with VTE (allele frequency, 2.35%) and controls (1.12%), with an odds ratio (OR) of 2.15 (95% confidence interval, 1.16-3.99). PC p.Arg189Trp carriers were prevalent among Chinese and Malay patients with VTE in Singapore, with allele frequencies of 10.53% and 22.73%, respectively. Carriers of PC p.Lys193del were identified among Japanese and Korean patients with VTE (0.87% and 2.35%, respectively) and controls (0.36% and 1.07%, respectively), with the OR for VTE not being significant, and Chinese patients with VTE in Singapore (5.26%). In contrast, no carriers of PS Tokushima and two PC gene variants were found among patients with VTE or controls from Hungary, Brazil, or Indians in Singapore. CONCLUSION: The three variants were prevalent among East and Southeast Asians, having some differences in geographic distribution, but were absent among Caucasian subpopulations and Brazilians.