OBJECTIVETo explore F (13) A gene mutation in a pedigree with hereditary coagulation factor XIII (FXIII) deficiency.

METHODSThe FXIII deficiency was diagnosed by clot solubility test and other standard laboratory clotting tests. All exons, exon-intron boundary sequences of F(13) A gene were amplified by PCR and the products were sequenced directly. Any mutation identified by direct sequencing was confirmed by reverse sequencing. The mutation identified in the proband was screened in the family members.

RESULTSThe assays of PT, Qiulan, fibrinogen leveling, platelet counts, bleeding time were normal and the clot solubility test was positive in the proband. The homozygous deletion of 33 nucleotides (127067de133) in exon 10 of F(13) A gene which resulted in deletion of 11 amino acids in FXIIII A protein with 720aa residues was identified in the proband. Family studies showed that the mutation was inherited from the parents both of whom carried the heterozygous deletion mutation.

CONCLUSIONThe homozygous 127067de133 mutation of F(13) A gene is responsible for the disorder of the pedigree.