Severe factor X deficiency due to a homozygous mutation (Cys364Arg) that disrupts a disulphide bond in the catalytic

T Todd1, D J Perry, E Hayman

  • 1Department of Haematology, Addenbrooke's Hospital, Hills Road, Cambridge, UK. tony.todd@addenbrookes.nhs.uk

Severe factor X deficiency (<0.01 IU mL(-1)) is a rare disorder producing a major bleeding tendency including umbilical cord, joint and intracranial haemorrhage. We present the first case of a child homozygous for a g.1177T > C missense alteration, predicted to disrupt the catalytic domain, and resulting in severe FX deficiency. The child suffered intracranial haemorrhage and now receives regular prophylaxis with a prothrombin complex concentrate. Our experience and a review of the literature suggest that optimal frequency of dosing is likely to be two or three times weekly and that the risk of thrombosis is very small.

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