Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Factor V Deficiency”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

A case of congenital factor V deficiency combined with multiple congenital anomalies: successful management of palatoplasty.

A patient with congenital factor V deficiency combined with mental retardation and several congenital anomalies including cleft palate, dwarfism, microcephaly and right hydrocele testis is described. The levels of factor V activity and factor V antigen of plasma were significantly decreased. The platelet lysate obtained from him also showed a significantly low level of factor V activity. Palatoplasty and tooth extraction were successfully performed under transfusion therapy with fresh-frozen plasma.

Abnormalities, Multiple↗

Rescue of fatal neonatal hemorrhage in factor V deficient mice by low level transgene expression.

Factor V (FV) is a critical component of the coagulation cascade. FV-deficient patients suffer moderate to severe bleeding, though residual FV activity is detectable in nearly all cases. In contrast, FV-deficient mice die either during mid-embryogenesis, or of massive perinatal hemorrhage. In order to examine the requirements for FV in murine embryogenesis and hemostasis, we generated transgenic mouse lines expressing a Fv minigene under control of either the tissue-specific albumin (Malb) or rat platelet factor 4 (Rpf4) promoter. A total of 12 Malb and 3 Rpf4 lines were analyzed. Though expression in the target tissue was detectable in most lines by RT-PCR, only low levels of transgene expression were achieved (<3% of endogenous Fv in all lines). Despite a low level of Fv transgene expression, rescue of the lethal Fv-/- phenotype was observed with one of the Malb transgenic (Tg+) lines. However, rescue appeared to be incomplete with continued loss of >1/2 of expected Tg+,Fv-/- mice in early embryogenesis. Rescued Tg+,Fv-/- mice have undetectable FV (<0.1%) in both plasma and platelet compartments, but survive the perinatal period and mature to adulthood without spontaneous hemorrhage. We conclude that FV present at <0.1% is sufficient to support postnatal survival. Failure of the Malb transgene to rescue the midembryonic block suggests that FV expression is required during mammalian development at higher levels or with a different tissue-specific or temporal pattern. Taken together, these data may explain the observation of residual FV activity in most human FV-deficient patients due to early embryonic lethality in those absolutely deficient, and suggest that minimal levels of FV expression, below the level of detection, also may be sufficient to support survival in humans.

Acute Disease↗

Arg2074Cys missense mutation in the C2 domain of factor V causing moderately severe factor V deficiency: molecular characterization by expression of the recombinant protein.

Factor V (FV) deficiency is a rare bleeding disorder whose genetic basis has been described in a relatively small number of cases. Among a total of 12 genetic defects reported in severely or moderately severe deficient patients, 3 were missense mutations and in no case was the mechanism underlying the deficiency explored at the molecular level. In this study, a homozygous missense mutation at cDNA position 6394 in exon 23 of the FV gene was identified in a 22-year-old Italian patient. This mutation causes the replacement of arginine 2074 with a cysteine residue (Arg2074Cys) in the C2 domain of the protein. The effect of the Arg2074Cys mutation on FV secretion, stability, and activity was investigated. Site-directed mutagenesis of FV cDNA was used to introduce the identified mutation, and wild-type as well as mutant FV proteins were expressed by transient transfection in COS-1 cells. An enzyme immunoassay detected low FV antigen levels both in the conditioned media of cells expressing the mutant protein and in cell lysates. Metabolic labeling and pulse-chase experiments confirmed that the mutation caused an impaired secretion of FV associated with rapid intracellular degradation. In addition, evaluation of wild-type and mutant coagulant activity demonstrated that the FV molecules carrying the Arg2074Cys mutation have reduced activity. These findings, beside confirming the structural and functional importance of the arginine 2074 residue, demonstrate that its substitution with a cysteine impairs both FV secretion and activity.

Adult↗

Discrimination between normal wildtype and carriers of coagulation factor V Leiden mutation by the activated protein C resistance test in the presence of factor V deficient plasma.

Blood samples from 104 patients with clinically suspected thrombophilia were analyzed for coagulation factor V Leiden mutation (1691, G-->A) by allele-specific polymerase chain reaction. In 86 individuals (82.7%), the mutation was not detectable, whereas 15 patients (14.4%) were heterozygous and three patients (2.9%) were homozygous for factor V Leiden mutation. Plasma samples from these individuals were also tested for functional resistance of coagulation factor V to activated protein C (activated protein C resistance). This test was performed on a Schnitger-Gross coagulometer using an activated partial thromboplastin time-based activated protein C resistance test modified by applying a 1 : 5 dilution with factor V-deficiency plasma. All the individuals negative for factor V Leiden mutation were also negative in the functional activated protein C resistance test. On the other hand, all patients carrying the mutation revealed pathologic results in the activated protein C resistance test. The cutoff value for the activated protein C resistance index (> or = 1.7 = negative) was determined by testing 31 male and female blood donors. One of them was heterozygous for factor V Leiden mutation and had an activated protein C resistance index of 1.4, whereas those without factor V Leiden mutation had an activated protein C resistance index of 1.9 +/- 0.1 (mean +/- SD). Patients with clinically suspected thrombophilia without factor V Leiden mutation had an activated protein C resistance index of 2.1 +/- 0.2 (mean +/- SD), whereas patients heterozygous for the mutation had an index of 1.5 +/- 0.1 (mean +/- SD). Within the group of patients carrying the mutation, the activated protein C resistance test even distinguished between heterozygous and three homozygous (activated protein C resistance 1.0 to 1.2) carriers. The data demonstrate that the activated protein C resistance test in the presence of factor V-deficiency plasma provides a clear-cut discrimination between normal wildtype and carriers of factor V Leiden mutation with a sensitivity and specificity of 100%. Verification of positive activated protein C resistance tests can be performed easily with a simple and reliable polymerase chain reaction protocol for the 1691, G-->A mutation.

Base Sequence↗

The localization of factor V within normal human platelets and the demonstration of a platelet-factor V antigen in congenital factor V deficiency.

Separation of human platelets from plasma by a modified gel-filtration technique reveals very low levels of factor-V activity of the platelet suspension. Repeated freezing and thawing increases the factor-V activity in various factor-V assays. This activity neutralized the inactivating effect of a rabbit-antihuman factor V antibody to plasma factor V, while intact platelets had almost no such capacity. Washed and normal platelets and gel filtered platelets showed marked positive fluorescence after treatment with antifactor V serum and FITC labelled sheep antirabbit immunoglobulin. Fluorescence was inhibited by previous incubation of the antifactor V serum and platelet lysates. Platelets of a factor V deficient patient showed the same fluorescence pattern as normal platelets indicating that they contained a factor V antigen. These platelets showed after lysis no effect in various factor V assays. From these studies it is concluded that the localization of factor V is within the platelets.

Antigens↗

Acquired factor V deficiency in a patient with pulmonary tuberculosis.

A 29 yr old man with pulmonary tuberculosis and concomitant acquired plasma coagulation factor V deficiency is reported. The case is discussed together with three previously described cases. The bleeding tendency in a patient with pulmonary tuberculosis may be caused by a coagulation factor antibody and may be corrected by chemotherapy, as in the case described. Special therapeutic approaches are required in some cases.

Adult↗

A novel two base pair deletion in the factor V gene associated with severe factor V deficiency.

We studied a family in which the proband, a 13-year-old boy, had unmeasurable plasma levels of coagulation factor V antigen and activity. Clinical symptoms were severe, with several episodes of haemorrhages in the mucosal tracts (gastrointestinal, nose and urinary) and recurrent haemarthroses that caused permanent arthropathy. Sequence analysis of the factor V gene demonstrated the presence of a novel 2 base pair (bp) homozygous deletion in exon 13 at positions 2833-2834. This mutation, present in the heterozygous state in the asymptomatic mother and absent in the healthy brother, introduced a frameshift and a premature stop at codon 900. This would predict the synthesis of a truncated factor V molecule, lacking part of the B domain and the complete light chain. Because of the existence of a surveillance mechanism that selectively recognizes and degrades mRNA molecules carrying premature termination codons, we analysed the relative abundance of mutant vs. wild-type mRNA molecules in the platelets of the heterozygous proband's mother. The mutant mRNA was significantly reduced in amount (mutant/wild-type ratio 0.35). This is the first reported mutation in the factor V gene causing severe factor V deficiency, the effect of which was quantitatively analysed at mRNA level.

Adolescent↗

[A novel mutation causes congenital factor V deficiency].

OBJECTIVE: To investigate the gene defect in a hereditary coagulation factor V (FV) deficiency family. METHODS: The plasma FV actigen was measured by one-stage clotting assay. The FV antigen was assayed by Biotin-Avidin enzyme linked immunosorbent assay (BA-ELISA). The full length of exon 1 to exon 25 and the 5' untranslated sequence of FV genomic DNA were analyzed by polymerase chain reaction (PCR) and direct sequencing of the amplified fragments, meanwhile the defect was identified by T/A cloning sequencing. RESULTS: The plasma coagulant activity and amount of FV of the proband were marked deficient (1% and 1.54%, respectively). DNA sequence analysis for the proband revealed a causative mutation in a heterozygous status. It was one base pair deletion in exon 4 at nucleotide 675 inherited from her mother. CONCLUSIONS: A novel mutation in the FV gene was identified in the proband with congenital FV deficiency. The mutation was 675delA in exon 4 resulting in a frameshift and a premature termination codon.

Adolescent↗

Wilson's disease with concomitant beta thalassaemia and factor V deficiency.

A case of late presentation of Wilson's disease in a female with a thalassaemic trait is reported in whom diagnosis of Factor V deficiency was made. Despite ignoring the disease for years the patient had compensated cirrhosis. She had a dramatic family history of Wilson's disease affecting at least two brothers and two sisters. Moreover, her haematologic problems were not clinically revealed until diagnosis had been made on the basis of suspicions arising from laboratory results. The therapy of choice for hepatolenticular degeneration was not feasible due to the patient's refusal. Zinc salts were, therefore, administered. To our knowledge the association of such rare genetic disorders has not been reported.

Factor V Deficiency↗

Abnormal formation of the prothrombinase complex: factor V deficiency and related disorders.

A membrane-bound, Ca2-dependent complex of the cofactor factor Va and the enzyme factor Xa comprises the prothrombinase coagulation complex, which catalyzes the proteolytic conversion of prothrombin to thrombin. In normal hemostasis, the platelet is presumed to supply the surface membrane and thus constitutes the site at which an enzymatically functional complex assembles and thrombin generation occurs. Factor Va, the two subunit protein produced by thrombin activation of factor V, is an essential, nonenzymatic cofactor of the prothrombinase complex. Factor Va performs its cofactor role in part by binding to the platelet membrane and functioning as the membrane receptor for factor Xa in a 1:1 stoichiometric complex of high affinity (Kd = 10(-10) M). Factor Va also appears to participate in the binding of prothrombin to the enzymatic complex. Because deletion of factor Va from the prothrombinase complex decreases the rate of thrombin generation by four orders of magnitude, the essential role it plays is easily understood. Therefore, in the evaluation of factor Va function in the prothrombinase complex, the ability of factor Va to support various binding interactions with the platelet, factor Xa, and prothrombin must be considered. Factor Va can be made available from two potential blood compartments: the plasma and platelets. Approximately 80 per cent of the total blood factor V circulates in plasma whereas the remaining 20 per cent is contained within platelet granules. The relative contribution of plasma versus platelet factor V to factor Va binding interactions in the prothrombinase complex are not clearly defined. However, data from our laboratory and several others suggest that factor V stored and released from platelets is of utmost importance in maintaining normal hemostasis. A discussion of these data relative to congenital and acquired deficiencies of both plasma and platelet factor V is the subject of this report.

Blood Platelets↗

Acute cardiac tamponade secondary to congenital factor V deficiency.

Spontaneous cardiac tamponade secondary to a congenital coagulation defect has never been reported. We report a case of acute cardiac tamponade in a patient with a known factor V deficiency. This patient presented with classic signs of acute cardiac tamponade and an enlarged cardiac silhouette. After diagnostic two-dimensional echocardiography and treatment with fresh-frozen plasma, the patient underwent emergent pericardiocentesis followed by complete pericardiectomy.

Acute Disease↗

Severe factor V deficiency and neonatal intracranial haemorrhage: a case report.

We report a case of severe factor V (FV) deficiency (<1%) associated with multiple episodes of intracranial bleeding which presented at birth. The clinical course was further complicated by the development of an inhibitor, episodes of sepsis and cardiac failure. The management using virally inactivated FFP and platelets is discussed.

Bacterial Infections↗

Molecular characterization of a type I quantitative factor V deficiency in a thrombosis patient that is "pseudo homozygous" for activated protein C resistance.

Resistance to activated protein C (APC), which is associated with the FV Leiden mutation in the large majority of the cases, is the most common genetic risk factor for thrombosis. Several laboratory tests have been developed to detect the APC-resistance phenotype. The result of the APC-resistance test (APC-sensitivity ratio, APC-SR) usually correlates well with the FV Leiden genotype, but recently some discrepancies have been reported. Some thrombosis patients that are heterozygous for FV Leiden show an APC-SR usually found only in homozygotes for the defect. Some of those patients proved to be compound heterozygotes for the FV Leiden mutation and for a type I quantitative factor V deficiency. We have investigated a thrombosis patient characterized by an APC-SR that would predict homozygosity for FV Leiden. DNA analysis showed that he was heterozygous for the mutation. Sequencing analysis of genomic DNA revealed that the patient also is heterozygous for a G5509-->A substitution in exon 16 of the factor V gene. This mutation interferes with the correct splicing of intron 16 and leads to the presence of a null allele, which corresponds to the "non-FV Leiden" allele. The conjunction of these two defects in the patient apparently leads to the same phenotype as observed in homozygotes for the FV Leiden mutation.

Adult↗