Heterozygous factor XI deficiency associated with three novel mutations.

To determine the utility of single-stranded conformation polymorphism (SSCP) analysis for screening mutations in the factor XI (fXI) gene, we investigated three patients with heterozygous factor XI deficiency. DNA sequence analysis confirmed three novel mutations; a CGC --> TGC (Arg308Cys) mutation in exon 9, a GCT-->GTT (Ala412Val) mutation in exon 11 and an AGC --> AGA (Ser576Arg) mutation in exon 15. We postulated on the structural implications of these missense mutations. Our results demonstrated that genotypic analysis is a useful tool for conclusive differentiation between heterozygous factor XI deficiency and normal subjects.