Moreover, the high proportion of repetitive elements, mainly Alu sequences, in and around SERPINC1 [11], together with the relevance that these elements play in the generation of SVs affecting this gene and causing antithrombin deficiency [12], encouraged us to carry out a comprehensive analysis of the involvement of SVs in antithrombin deficiency. The gene discussed is SERPINC1; the disease is hereditary antithrombin deficiency.