Molecular analysis of patients with severe congenital factor X deficiency: First report from north and northwest of Iran.

Background Congenital FX deficiency is an extremely rare autosomal recessive disorder, mostly present in regions with a high rate of consanguinity, with an incidence of approximately 1:2,000,000 in the general population. The aim of this study was to evaluate the clinical manifestations and to provide a molecular analysis of 14 patients with homozygous factor X deficiency. Methods We evaluated the results of clinical and molecular characterization of 14 new cases (10 males, 4 females aged from 4 to 17 years) of FXD (FX activity <1%) in North and Northwest of Iran. FXD was diagnosed by clinical findings and routine laboratory tests. The PCR products of all the eight exons and their intron-exon boundaries were sequenced using DNA sequencer. Results Mean age of patients and mean age at diagnosis were 9 and 2.5 years, respectively. The molecular analysis revealed five different mutations, all of them were previously described. Molecular analysis showed five different homozygous and double heterozygous mutations including Arg-1Thr, Cys81Tyr, Gly78Asp, IVS1+3, and IVS2-3. Discussion The study of a large population of factor X patients from three institutions indicated that FXD was one of the most serious among rare bleeding disorders and that factor X gene mutation may be related to bleeding tendency in patients.