Novel mutations in the Factor VII gene of Taiwanese Factor VII-deficient patients.

The genetic defects of four Taiwanese patients with factor VII (FVII) deficiency were studied. FVII activity and antigen levels were < 1 u/dl and 125.7 u/dl (patient I), < 1 u/dl and < 1 u/dl (patient II), 3.4 u/dl and 5.9 u/dl (patient III), and 1.2 u/dl and 30.4 u/dl (patient IV) respectively. The 5' flanking region, and all exons and junctions were amplified using polymerase chain reaction and sequenced. Patient I was homozygous for a 10824C-->A transversion with Pro303-->Thr mutation in exon 8. In patient II, a heterozygous transversion, 9007+1G-->T at the IVS6, a heterozygous decanucleotide insertion polymorphism at -323 (both mutations present in his father) and a heterozygous deletion, del TC (26-27) in exon 1A (originating from his mother) were identified. Patient III had a homozygous 10961T-->G transversion with His348-->Gln mutation in exon 8. Patient IV had a heterozygous 10902T-->G transversion with Cys329-->Gly mutation in exon 8 (transmitted to her second son) and a heterozygous decanucleotide insertion polymorphism at -323 (transmitted to her third son). All but one of the FVII gene mutations detected in the four patients have not been previously reported. In conclusion, four novel mutations of the FVII gene in Taiwanese, including two missense mutations in exon 8, one point mutation at the exon 6 splice site and one deletion in exon 1A, were identified.