HLA typing in a new family with Fletcher factor deficiency.

In a nonrelated white family, the Fletcher factor level in the father was 0.41 U/ml and in the mother, 0.30 U/ml (controls, 0.75-1.25 U/ml). One sibling with recurrent epistaxis had a level of 0.012 U/ml, whereas the other without tendency to spontaneous bleeding had levels between 0.75 and 0.32 U/ml. This suggests autosomal recessive transmission with clinical symptoms when the defect is homozygous. HLA antigens were studied to determine whether characters of the histocompatibility system and this defect are linked: we determined that the gene(s) of the disease is (are) not shared on the HLA complex.