Factor V Leiden is not responsible for stroke in patients with sickling disorders and is uncommon in African Americans with sickle cell disease

Cerebrovascular accidents in patients with sickle cell anemia are among the most devastating complications of the disease. It has recently been demonstrated that some patients have a hypercoagulable state on the basis of the presence of an abnormal factor V molecule, factor V Leiden. We undertook this study to evaluate the presence of factor V Leiden in sickle cell patients with stroke. Eighty-two patients with either Hgb SS, Hgb SC, or Hgb Sβ⁺-thalassemia comprised the study population. Of the 82 patients in the study, 19 of them had a history of stroke. In our study population, none of the stroke patients possessed the factor V Leiden mutation. One of the non-stroke patients was a heterozygote for the mutation (P = 1.00). The overall frequency of the factor V Leiden allele in our population is 0.6%. The estimated prevalence for this mutation is reportedly between 3 and 7% in Caucasian populations. We conclude that the gene frequency for factor V Leiden is less common in Africa Americans with sickle cell disease. Furthermore, factor V Leiden does not appear to be responsible for the development of stroke in sickle cell patients. Am. J. Hematol. 54:12–15, 1997. © 1997 Wiley-Liss, Inc.