Abstract 30

Thromboembolism is increasingly recognized as a multifactorial disease. Some prothrombotic polymorphisms, such as G1691A in factor V (FV Leiden), G20210A in factor II (FII), C1565T in GP IIIa and C677T in the methylentetrahydrofolate reductase (MTHFR), are associated with an increased risk of thrombosis. We evaluated the recurrence of these polymorphisms in three at risk pediatric populations: catheterized newborns, leukemic and thalassemic patients. To allow case-control studies we established the prevalence of these polymorphisms in the Southern Italy population examining 80 subjects with the absence of familial and personal history of thrombotic events (see table). The DNA analyzed was performed with PCR amplification and digestion with restriction enzymes and electrophoresis on polyacrilamide gel. In thalassemic patients we found 4 heterozygous subjects for FV Leiden out of 85 examined cases (4.7%). Only one thrombotic events was observed as a case of stroke in a 10 years old thalassemia intermedia patient at the beginning of her transfusion regimen. Based on the results of this study, the routine screening of children with thalassemia major for FV Leiden mutation should not be recommended; instead it may be useful to evaluate a larger group of thalassemia intermedia patients to propose such screening in all intermedia thalassemic patients, especially before starting a transfusion regimen. The analysis of these polymorphism is actually under observation in the other two groups: catheterized newborns and leukemic patients.

Table 1 No caption available.
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