PRENATAL-DIAGNOSIS IN COMBINED ANTITHROMBIN AND FACTOR-V GENE MUTATION

We report prenatal diagnosis in a family with combined antithrombin de ficiency (type II heparin binding site) and factor V 506 Arg to Gin mu tation. Both clinically unaffected parents are heterozygous for the an tithrombin mutation, which results in a 99 Leu to Phe substitution, an d the father is also heterozygous for the factor V gene defect. There is one daughter, homozygous for the antithrombin and heterozygous for the factor V mutations, who suffered a right-sided hemiparesis at the age of 4 months due to occlusion of the left middle cerebral artery an d a large left sided infarct followed by further thromboembolic events . The family requested prenatal diagnosis and chorionic villi was samp led at 12 weeks gestation, The fetus was shown to be heterozygous for the antithrombin and factor V gene mutations, the same genotype as the unaffected father. No further intervention was considered necessary. To our knowledge this is the first report of prenatal diagnosis in ant ithrombin deficiency.