ALLELIC FREQUENCY AND MINOR VARIATIONS OF THE FACTOR V R2 HAPLOTYPE IN JAPANESE POPULATION

Abstract number: P-T-039

Yamazaki¹ T., Okada¹ H., Toyoda² Y., Kunishima¹ S., Hamaguchi¹ M., Saito³ H., Kojima² T.

¹¹Department of Hemostasis and Thrombosis, Clinical Research Center, Nagoya Medical Center ²²Department of Medical Technology, Nagoya University School of Health Sciences ³³President, Nagoya Central Hospital, Nagoya, Japan

How-to-cite Yamazaki T, Okada H, Toyoda Y, Kunishima S, Hamaguchi M, Saito H, Kojima T. ALLELIC FREQUENCY AND MINOR VARIATIONS OF THE FACTOR V R2 HAPLOTYPE IN JAPANESE POPULATION. J Thromb Haemost 2007; 5 Supplement 2: P-T-039

Abstract

Introduction: The Factor V (FV) R2 haplotype (FV-R2), which consists of multiple nucleotide substitutions on one allele, is a common genetic variation among several distinct populations. Because FV-R2 has been found in African populations, it has been expected that also Asian populations have FV-R2. However, it has not yet been studied. We also have focused on whether minor racial variations of FV-R2 are present or not.

Methods: Genomic DNA samples were obtained from 207 healthy Japanese individuals. DNA fragments spanning exon 13 of the FV gene were PCR-amplified and sequenced.

Results: Among 207 Japanese individuals 20 heterozygous and 1 homozygous carriers of FV-R2 were identified. Thus, allelic frequency of FV-R2 in Japanese population is calculated to be 5.3%, which is similar to those in other populations. We found 4 differences in nucleotide substitutions (A2540C, A2863G, C3943A and C4038T) between the Japanese FV-R2 and the Italian FV-R2 originally reported by Bernardi and Castoldi et al. All Japanese FV-R2 alleles detected in this study carried the same nucleotide substitutions in exon 13.

Conclusions: Our result demonstrates that FV-R2 is present also in Japanese population as expected before. The Italian group has found no variation in exon 13 of FV-R2 in Italian population. In contrast, the Japanese FV-R2 differs from the Italian FV-R2 at 4 sites in exon 13. It is indicated that FV-R2 is not unique among different populations, but there are minor racial variations. FV-R2 has been supposed to be a mild risk factor of thrombosis and associated with mild APC resistance. However, several previous reports have described controversial results. It has been reported that M385T, H1299R, M1736V and D2194G mutations are mainly responsible for the thrombotic tendency and the mild APC resistance associated with FV-R2. However, other minor variations of nucleotide substitutoins could affect the plasma phenotypes of FV-R2 carriers and account for the controversial results obtained in different populations.

To cite this abstract use the following format:

Journal of Thrombosis and Haemostasis 2007; Volume 5, Supplement 2: abstract number

Session Details

Date:	01/08/2007
Time:	00:00-00:00
Session name:	XXIst ISTH Congress
Subject:
Location:	Oxford, UK
Presentation type:
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