[Antithrombin deficiency and thrombosis in a young child]

Thromboses represent a rare event in children and may be due to a deficiency of antithrombin.

A 10-year-old boy developed thrombosis due to a congenital quantitative deficiency in antithrombin, confirmed by molecular biology. His father was diagnosed with the same deficiency. The child was first treated with heparin and is now on antivitamin K. He is well 26 months after diagnosis.

When a young patient presents with a thrombotic event, a congenital deficiency in one of the inhibitors of coagulation, one of which is antithrombin, should be looked for and the condition treated as soon as possible.