A case of Hageman factor deficiency with myeloid leukaemia.

The co-existence of blastic transformation of chronic myeloid leukaemia and an isolated deficiency of coagulation factor XII (Hageman Factor), is reported. In the absence of any evidence of factor XII deficiency in the patient's siblings and children, it is uncertain if this represents an acquired factor XII deficiency due to myeloid leukaemia, or the coincidental occurrence of myeloid leukaemia with this autosomal recessive condition.