Molecular characterization of an Italian patient with plasminogen deficiency and ligneous conjunctivitis

Plasminogen deficiency is a rare disease characterized by ligneous conjunctivitis and infections. We observed a 3-year-old Italian boy presenting ligneous conjunctivitis and low plasma levels of plasminogen. Twenty-three different mutations on the PLG gene have been reported to date, but mutation analysis had been troublesome for the presence of highly homologous genes. The aim of the study was to identify the underlying mutation avoiding coamplification of unwanted genetic materials using a long polymerase chain reaction strategy, instead of the previously reported subcloning methods. By this simple strategy the complete sequence analysis of PLG gene was performed, and a previously reported missense homozygous mutation (K19E) was identified

Combined FV and FVIII deficiency

Inherited deficiencies of plasma proteins involved in blood coagulation generally lead to lifelong bleeding disorders. The severity of these disorders is generally inversely proportional to the degree of factor deficiency. Among all the autosomal recessive rare bleeding disorders, which include afibrinogenaemia, factor (F) II, FV, FV + VIII, FVII, FX, FXI, FXIII, the combined deficiency of coagulation FV and FVIII (F5F8D or FV + FVIII) is exceptional because it is due to mutations in genes encoding proteins involved in the FV and FVIII intracellular transport (LMAN1 and MCFD2) rather than DNA defects in the genes that encode the corresponding coagulation factors. F5F8D is estimated to be extremely rare (1:1.000.000) in the general population, but an increased frequency is observed in regions where consanguineous marriages is practiced. F5F8D is characterized by concomitantly low levels (usually between 5% and 20%) of both FV and FVIII, and is associated with a mild to moderate bleeding tendency. Treatment of bleeding episodes requires a source of both FV and FVIII; replacement of FV is achieved through the use of fresh frozen plasma, and that of FVIII by desmopressin or specific FVIII concentrates, plasma-derived or recombinant FVIII products. We focus here on the clinical, molecular, treatment-related and diagnostic features of F5F8

Combined factor V and factor VIII deficiency

Combined deficiency of factor V (FV) and factor VIII (FVIII) (F5F8D, or FV+FVIII) is a autosomal recessive bleeding disorder caused by mutations in genes encoding two components of the endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC-53), that is, lectin mannose binding protein ( LMAN1) and multiple coagulation factor deficiency 2 ( MCFD2), involved in the FV and FVIII intracellular transport rather than by DNA defects in the genes that encode the corresponding coagulation factors. F5F8D is estimated to be extremely rare (1:1,000,000) in the general population, but an increased frequency is observed in regions where consanguineous marriages are practiced. F5F8D is characterized by concomitantly low levels (usually between 5% and 20%) of both FV and FVIII and is associated with a mild to moderate bleeding tendency. Treatment of bleeding episodes requires a source of both FV and FVIII; replacement of FV is achieved only through use of fresh-frozen plasma (FFP) and replacement of FVIII by FFP and desmopressin or specific FVIII concentrates (plasma-derived or recombinant FVIII products

CYP2C9 genotypes and dose requirements during the induction phase of oral anticoagulant therapy

Objective: Variant alleles of the CYP2C9 gene encoding the cytochrome P450 (CYP) enzyme (2C9*2 [Arg144Cys] and 2C9*3 [Ile359Leu]) are known to increase the anticoagulant effect of warfarin and decrease the mean daily dose required to maintain the international normalized ratio (INR) of the prothrombin time within the target therapeutic range. However, little information is available on the effect of CYP2C9 polymorphisms; on dose requirements during the most critical step of anticoagulant therapy, the induction phase. Methods. This retrospective study evaluated the dosages given to 125 patients who started therapy with warfarin in a clinical center where physicians used the same approach for dosing and frequency of monitoring. CYP2C9 allelic variants were evaluated by polymerase chain reaction followed by restriction enzyme analysis. Results. From the time of the first INR estimate (day 4) until the end of the induction phase (arbitrarily established at day 24), patients with 2C9*2 or 2C9*3 variant alleles required lower mean daily doses than patients carrying only wild-type alleles 2C9*1 (-17% and -40%, P < .0001). They also more frequently had INR values above the upper limit of the target range (3.0) (65% for 2C9*2/- and 66% for 2C9*3/- versus 33% for 2C9*1/*1; P = .006 and .012, respectively). Conclusions: The requirement of smaller doses of warfarin in relation to CYP2C9 polymorphisms is already manifest on the fourth day of treatment, at the time of the first INR estimate. CYP2C9 genotyping is as yet not warranted, but frequent INR monitoring with appropriate dose adjustments is recommended during the first 3 weeks of treatment to avoid overanticoagulation and the inherent risk of bleeding in carriers of variant alleles