Antithrombin Gene (SERPINC1)mutation screen

Heritable antithrombin deficiency is an autosomal dominant disorder caused by mutations in the SERPINC1 gene. Heterozygous deficiency is usually associated with Antithrombin activity levels in the range of 40-60% of normal. Homozygosity is very rare and is often fatal in utero. Deficiencies are characterised as either Type I (a quantitative deficiency) or Type II (a qualitative deficiency). Type II deficiency is then further classified depending on whether the causative mutation affects the reactive site , the heparin binding domain or the reactive loop site. Phenotypic assays for Antithrombin deficiency can be complicated by acute clinical presentation and therapy, and so molecular confirmation of Antithrombin deficiency is of clinical utility.