Recurrent leg ulcers and arterial thrombosis in a 33-year-old homozygous variant of antithrombin.

We report here a homozygous variant case of antithrombin (AT) associated with arterial thrombosis and recurrent leg ulcers. The deep vein thrombosis was recognized by the venogram of his pelvic veins. His leg ulcers were scattered around his left ankle and accompanied by lipodermatosclerosis, which was evident in venous insufficiency. The propositus had developed cerebral infarction 12 years prior to his leg ulcers. Coagulation study showed low heparin cofactor activity of his AT with a normal level of immunoreactive AT. Nucleotide sequence analysis of the exon 2 of his AT gene showed Arg47-Cys mutation, leading to the lack of affinity of AT for heparin. The propositus is a homozygote for this abnormality.