The factor V Leiden mutation in Japanese couples with recurrent spontaneous abortion

Thrombosis of placental vessels can be a major cause of recurrent spontaneo us abortion (RSA), The factor V Leiden (FVL) mutation, a single point mutat ion in the factor V gene, is the most common genetic predisposition to thro mbosis in European countries and the United States. However, even among Cau casian populations, the association between the FVL mutation and RSA is sti ll controversial. The objectives of the present study were to investigate t he prevalence of the FVL mutation in Japanese women who have experienced RS A and to clarify the contribution of the FVL mutation to recurrent miscarri ages. A total of 52 Japanese women with a history of three or more consecut ive idiopathic first trimester miscarriages and 41 of their male partners w ere studied, The control group consisted of 55 parous women without obstetr ic complications. Peripheral blood cell DNA was examined for the presence o f the FVL alleles by polymerase chain reaction with Mnl I restriction fragm ent length polymorphisms. None of the 52 women with RSA and the 41 partners carried the mutation. We also found no subject carrying the FVL alleles in the control group. These results suggest that the FVL alleles are not conc entrated in women with RSA at least to clinically significant levels and th at there is no apparent association between the FVL mutation and RSA in our Japanese population.