Severe high-molecular-weight kininogen deficiency: clinical characteristics, deficiency-causing KNG1 variants, and estimated prevalence.

Background: Severe high-molecular-weight kininogen (HK) deficiency is a poorly studied autosomal recessive contact system defect caused by pathogenic, biallelic KNG1 variants.

Aim: We performed the first comprehensive analysis of diagnostic, clinical, genetic, and epidemiological aspects of HK deficiency.

Methods: We collected clinical information and blood samples from a newly detected HK-deficient individual and from published cases identified by a systematic literature review.

Haemophilia care in Latin America: Assessment and perspectives.

Introduction: The study is the first application of the Principles of Haemophilia Care for Europe (PHCE) in other regions of the world, specifically in Latin America.

Objective: To identify strengths in the care of haemophilia, and the aspects that should be improved.

Methods: The information was obtained through a questionnaire designed according to the PHCE and answered by specialists in mid-2016.

A novel fibrinogen mutation: g. 3057 C > T (p. Arg104 > Cys) impairs fibrinogen secretion.

Background: Abnormal fibrinogens can be caused by clinically silent hereditary mutations. A new case was detected accidentally in an 11-year-old girl when routine pre-operative coagulation tests were performed for nasal turbinate surgery.

Methods: The fibrinogen genes FGA, FGG and FGB were sequenced using standard protocols.

Episodic replacement of clotting factor concentrates does not prevent bleeding or musculoskeletal damage - the MUSFIH study.

Patients And Methods: A longitudinal study was carried out in 255 children from 10 centres in nine developing countries over 5 years to assess the musculoskeletal outcome of children on episodic factor replacement. Outcome was documented by assessment of the annual joint bleeding rate (AJBR), WFH clinical and Pettersson radiological joint scores as well as the FISH score for activities. Of the 203 patients for whom data was available at the end of 5 years, 164 who had received only episodic treatment are included in this report.

Favourable impact of regular swimming in young people with haemophilia: experience derived from 'Desafio del Caribe' project.

Swimming is beneficial for persons with haemophilia (PWH) providing good maintenance of the cardiovascular and musculoskeletal system and improving many psychological characteristics. In the Desafío del Caribe Project, young PWH from Venezuela and Mexico took part in an open water competition in the Gulf of Mexico under a multidisciplinary team supervision. Eight severe haemophilia A, two moderate haemophilia A, one severe haemophilia B and two moderate haemophilia B subjects were included.

Musculoskeletal evaluation in severe haemophilia A patients from Latin America.

There is a paucity of literature on haemophilia treatment in Latin American countries, a region characterized by rapidly improving systems of care, but with substantial disparities in treatment between countries. The aim of this study was to evaluate the musculoskeletal status of haemophilia patients from Latin America and to examine the relationship between musculoskeletal status and treatment practices across countries. The Committee of Latin America on the Therapeutics of Inhibitor Groups conducted a survey of its member country representatives on key aspects of haemophilia treatment in 10 countries.

Occurrence of thrombosis in rare bleeding disorders.

Paradoxically, there are reports of thrombotic events for some rare bleeding disorders associated with significant bleeding tendency. Afibrinogenemia, factor (F) VII, or FXI deficiencies are those most commonly associated with venous or arterial thrombosis. Pathogenesis is multifactorial and the main conditions associated with this complication relate to the coexistence of inherited or acquired thrombotic risk factors linked to certain specific characteristics of the underlying defect.

A novel mutation in the FGB: c.1105C>T turns the codon for amino acid Bβ Q339 into a stop codon causing hypofibrinogenemia.

Routine coagulation tests on a 14year-old male with frequent epistaxis showed a prolonged thrombin time together with diminished functional (162mg/dl) and gravimetric (122mg/dl) fibrinogen concentrations. His father showed similar aberrant results and sequencing of the three fibrinogen genes revealed a novel heterozygous nonsense mutation in the FGB gene c.1105C>T, which converts the codon for residue Bβ 339Q to stop, causing deletion of Bβ chain residues 339-461.

Replacement therapy for bleeding episodes in factor VII deficiency. A prospective evaluation.

Patients with inherited factor VII (FVII) deficiency display different clinical phenotypes requiring ad hoc management. This study evaluated treatments for spontaneous and traumatic bleeding using data from the Seven Treatment Evaluation Registry (STER). One-hundred one bleeds were analysed in 75 patients (41 females; FVII coagulant activity <1-20%).

Thrombosis in rare bleeding disorders.

Inherited deficiencies of blood coagulation factors are usually associated with lifelong bleeding tendency. In addition to Haemophilias A and B and von Willebrand disease, congenital deficiencies of such factors as fibrinogen, prothrombin (FII)), FV, FVII, FX, FXI, FXIII, and combined deficiencies occur and can lead to a diversity of clinical conditions. Paradoxically, for some of these disorders associated with significant bleeding tendency there are reports of thrombotic events, both arterial and venous.

Comprehensive care in hemophilia.

Hemophilia is a chronic and inherited X-linked bleeding disorder that requires life-long medical care. Hemophilia treatment is costly and complex partly because of the cost of the factor concentrates used in replacement therapy. However, the management of hemophilia is not based solely on achieving access to better treatment with safe factor concentrates; it also includes accurately diagnosing the disorder and providing specialized comprehensive care by a multidisciplinary team of specialists trained in hemophilia management.

Identification of factor VIII gene mutations in patients with severe haemophilia A in Venezuela: identification of seven novel mutations.

Haemophilia A is caused by mutations in the gene encoding coagulation factor VIII (FVIII). In severe Haemophilia A (sHA), two inversions are responsible for approximately 50% of the genetic alterations (intron 22 and intron 1 inversions). The other mutations are extremely diverse and each affected family generally has its own mutation.

Elective surgery in patients with congenital coagulopathies and inhibitors: experience of the National Haemophilia Centre of Venezuela.

Elective surgery in patients with congenital haemophilia with inhibitors carries a high risk of bleeding. However, inhibitor patients also have a high risk of haemarthroses and other orthopaedic complications, and surgery could improve their quality of life. Successful elective surgery has been reported in inhibitor patients under haemostatic cover with plasma-derived activated prothrombin complex concentrate (pd-aPCC) or recombinant activated factor VII (rFVIIa).

Radiosynoviorthesis in haemophilia: how safe?

One of the best procedures to prevent haemarthrosis in haemophilia has been radioactive synovectomy (radiosynoviorthesis). Since 1976 we have performed 119 radiosynoviortheses in 110 patients, aged from 3 to 40 years (mean 10), and of whom 71 were under 12 years of age. The knees were injected in 71, elbow in 29, ankles in 16, and shoulders in 3 cases.

Factor VII deficiency: clinical manifestation of 717 subjects from Europe and Latin America with mutations in the factor 7 gene.

The congenital FVII deficiency (FVIID) is a rare haemorrhagic disorder with an autosomal recessive pattern of inheritance. Data on phenotype and the genotype from 717 subjects in Central Europe (six countries), Latin America (Costa Rica, Venezuela) and United States, enrolled in the Greifswald Registry of FVII Deficiency were analysed. We detected 131 different mutations in 73 homozygous, 145 compound heterozygous and 499 heterozygous subjects.

Diagnosis and treatment of congenital hemophilia with inhibitors a Latin American perspective.

The Committee of Latin America on the Therapeutics of Inhibitor Groups (CLOTTING) is composed of a number of hemophilia specialists from Latin America. The group aims to encourage the adoption of a good standard of care for Latin American patients with hemophilia. The occurrence of inhibitors in patients with hemophilia poses clinical challenges, and it is estimated that between 1000 and 3000 patients in Latin America are affected by hemophilia with inhibitors.

Laboratory issues in bleeding disorders.

Selected laboratory issues critical for the appropriate diagnosis of haemophilia A and B, von Willebrand's disease (VWD) and more rare bleeding disorders (RBD) are discussed from a worldwide perspective. The overall picture that emerges is on the whole reassuring. Even in non-Western countries like Latin America, most cases of haemophilia are appropriately diagnosed.

Factor X deficiency: clinical manifestation of 102 subjects from Europe and Latin America with mutations in the factor 10 gene.

Inherited factor X deficiency (FXD) is a rare (1:1,000,000) recessive bleeding disorder. The clinical and laboratory phenotypes of FXD are poorly correlated and few regional studies on the genotype and the clinical manifestations of FXD are known. To understand the association between clinical manifestations and causative genotype, detailed evaluation of bleeding pattern in a high number of patients is needed.

Fibrinogen Guarenas, an abnormal fibrinogen with an Aalpha-chain truncation due to a nonsense mutation at Aalpha 467 Glu (GAA)-->stop (TAA).

Fibrinogen Guarenas is a dysfibrinogenemia with a nonsense mutation at G4731T that causes an Aalpha-chain truncation at Ser 466. This abnormal fibrinogen is associated with a bleeding diathesis, severe in the proposita and mild in one brother, even though the fibrinogen levels in plasma are normal. All other family members are asymptomatic.

Combined deficiency of factor V and factor VIII is due to mutations in either LMAN1 or MCFD2.

Mutations in LMAN1 (ERGIC-53) or MCFD2 cause combined deficiency of factor V and factor VIII (F5F8D). LMAN1 and MCFD2 form a protein complex that functions as a cargo receptor ferrying FV and FVIII from the endoplasmic reticulum to the Golgi. In this study, we analyzed 10 previously reported and 10 new F5F8D families.

Pharmacokinetics, thrombogenicity and safety of a double viral inactivated factor IX concentrate compared with a prothrombin complex concentrate.

Therapeutic options for developing countries have to assure an optimum safety and efficacy and low-cost antihaemophilic concentrates. A single blind randomized crossover study was carried out in 12 previously treated HB patients, comparing the pharmacokinetics (PK), thrombogenicity (TG) and safety of two plasma-derived double-inactivated (solvent/detergent heating at 100 degrees C, 30 min) factor IX (FIX) concentrates, UMAN COMPLEX DI (product A) [plasma-derived prothrombin concentrates (PCC)] and a high purity FIX concentrate AIMAFIX DI (product B, HPFIX). In a non-bleeding state, they received one single intravenous dose 50 IU FIX kg(-1) of PCC or HPFIX, and after a wash-out period of 14 days, the other product.

Platelet dysfunction-eosinophilia syndrome in parasitized Venezuelan children.

Platelet dysfunction was detected in six children with purpura and eosinophilia. We conducted clinical evaluations, hematologic and platelet function tests, clotting studies (bleeding time, prothrombin time, partial thromboplastin time, thrombin time, factor XIII, factor VIII, and von Willebrand factor), assays for IgG and IgM antibodies to platelets, and a search for stool parasites. Mild bleeding phenomena (ecchymoses, petechiae, epistaxis, and gingival) were transient.

Genotype-phenotype correlation in MYH9-related thrombocytopenia.

Mutation of the non-muscle myosin heavy chain type II-A results in MYH9-related hereditary macrothrombocytopenia (HMTC), including four autosomal dominant platelet disorders: May-Hegglin anomaly (MHA), Sebastian (SBS), Fechtner (FS) and Epstein (EPS) syndrome. Denaturing high-performance liquid chromatography (DHPLC) was optimised for rapid screening of the seven exons harbouring all but one of the previously reported mutations of MYH9. Individuals from 13 families with phenotypes suggestive of MYH9-related HMTC were screened for mutations by DHPLC followed by direct sequencing of samples with aberrant column retention time.