Resistance to activated protein C as a risk factor of stroke in a thalassemic patient.

It is well known that thalassemic patients exhibit an increased frequency of thrombotic events. Most individuals with resistance to activated protein C (APCR) are the result of a point mutation replacing Arg 506 with Gln in the factor V aminoacidic sequence (factor V Leiden). Recently APCR has been shown to account for up to 50% of cases of thrombophilia. In this report, we describe a 10 year old thalassemic intermedia patient heterozygous for Factor V R506Q who developed a stroke following transfusion. Coagulation laboratory values were all within the normal range and there was no evidence of a lupus anticoagulant. Computerized brain tomography showed an ischemic area in the left temporo-parietal region. At follow-up, plasma from the patient demonstrated APCR and molecular diagnostic testing revealed heterozygosity for factor V R506Q. We suggest that the heterozygosity for factor V Leiden could increase the thrombotic risk in thalassemia intermedia. We believe it may be beneficial to screen all intermedia thalassemic patients for APCR especially before starting a transfusional regimen.