One missense mutation in the factor X gene causing factor X deficiency - Factor X Kanazawa

We investigated the molecular basis of factor X deficiency in a Japanese pa tient whose factor X activity and antigen level were 45% and 50% of normal control values, respectively. All exons and intron/exon junctions of the fa ctor X gene were studied using a strategy combining polymerase chain reacti on (PCR) amplification and nonradioactive single-strand conformational poly morphism (SSCP) analysis. Exon 5, containing the DNA fragment of the proban d, showed aberrant migration by SSCP analysis. All exon-containing DNA frag ments amplified by PCR were sequenced, and it was revealed that the proband was a heterozygote for a G --> A substitution in exon 5 of the factor X ge ne of the proband. This mutation predicts an amino acid replacement of argi nine (Arg) for glycine (Gly) at codon 114 in the second EGF-like domain. (C ) 2001 The Japanese Society of Hematology.