Summary
We report 5 children from 3 families with homozygous antithrombin deficiency type
II affecting the heparin binding site (99 Leu to Phe mutation). Four children had
severe spontaneous thromboembolic events (deep leg or caval vein thrombosis, ischaemic
stroke) at one week, 3 months, 13 and 14 years of age. The fifth patient, a 17 year-old
boy was asymptomatic. Early manifestation of homozygous deficiency calls for prompt
and accurate diagnosis. In doubtful cases genetic analysis is required. Long-term
oral anticoagulation should be considered in affected individuals.
Keywords
Antithrombin-deficiency - thromboembolism - children