We investigated a family whose proband has a severe bleeding disorder and factor V antigenic and functional levels of 8% and less than 1% of control values, respectively. Molecular analysis of the factor V gene revealed a novel homozygous mutation in the last nucleotide of exon 10. 1701G>T causes activation of a cryptic exonic splice site in exon 10, which encodes part of the factor V heavy cha...

To investigate the molecular mechanisms of the quantitative factor V (FV) deficiency associated with the FV R2 haplotype, 4 missense mutations, Met385Thr, His1299Arg, Met1736Val, and Asp2194Gly, identified in the R2 haplotype allele, were analyzed by in vitro expression studies. The FV variant carrying all 4 mutations showed a markedly lower steady-state expression level than wild-type FV becau...

In 1954 Oeri et al. [1] described two young siblings with a lifelong history of a bleeding tendency related to a deficiency of both factor (F) V and FVIII. Reports of additional families in the late 1950s and 1960s [2–6] suggested that the common occurrence of FV and FVIII deficiencies was not a mere coincidence of parahemophilia and hemophilia A. This was further supported by the observation t...

BACKGROUND: Combined factor V and VIII deficiency (CF5F8D) is a rare autosomal recessive disorder, with an estimated prevalence of about 1:100,000 in the Jewish population. Affected individuals have between 5 and 30% of normal levels of factor V and VIII, whereas the levels of other plasma proteins are not altered. This bleeding disorder has been treated by replacement therapy with plasma infus...

A case of Factor V deficiency, the first case in Korea, is reported in a 9-year-old boy whose plasma concentration of Factor V was 6%. He complained of easy bruisability, prolonged bleeding from the mouth after minor trauma and hemarthrosis and flexion contracture of the right knee. His parents are heterozygous (maternal Factor V concentration 52%, paternal 40%).

Letters to the Editor will be published, if suitable, as space permits. They should not exceed 1,000 words (typed double-spaced) in length and may be subject to editing or abridgment. Since Owren's first description in 1947, 1 there have been several studies of congenital factor V deficiency associated with hemor-rhagic tendencies. This deficiency has also been associated six times with thrombo...

Factor V (FV; proaccelerin or labile factor) is the plasma cofactor for the prothrombinase complex that activates prothrombin to thrombin. FV deficiency can be caused by mutations in the FV gene or in genes encoding components of a putative cargo receptor that transports FV (and factor VIII) from the endoplasmic reticulum to the Golgi. Because FV is present in platelet alpha-granules as well as...