[Gene diagnosis of antithrombin deficiency and factor VII deficiency]

Since 1996 we have performed gene diagnosis of hereditary antithrombin deficiency and factor VII deficiency. We studied twenty-three patients with antithrombin deficiency and identified eighteen distinct gene mutations including single nucleotide substitutions, small nucleotide deletions, a small nucleotide insertion, and whole gene deletions. In two patients, however, we couldn't find out any mutations. We studied three patients with factor VII deficiency and identified three missense mutations. Two patients were homozygous for the mutation, respectively. Unexpectedly one patient was heterozygous for a missense mutation in the EGF domain though her plasma level of factor VII was reduced to 7% of normal. These results revealed that the genetic backgrounds and molecular mechanisms of antithrombin deficiency and factor VII deficiency were highly heterogeneous.