Second trimester antenatal diagnosis in rare coagulation factor deficiencies

Prenatal diagnosis in rare bleeding disorders-An unresolved issue?

Intracranial haemorrhage (ICH) is the most dreadful complication, and the main cause of death among patients with rare bleeding disorders (RBD) and prenatal diagnosis (PND) is a preventative lifesaving program. A total of 39 PNDs were reported in the literature through a search on PubMed, EMBASE, SCOPUS and Web of Science databases, most often for congenital factor (F) XIII and FVII deficiencies and rarely in FX, FV deficiencies and afibrinogenemia. The main cause to request a PND is ICH and related morbidity and mortality. Different molecular methods including direct sequencing and linkage analysis as well as polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for a specific mutation are the most common used methods for PND, while factor assay and combination of molecular and factor assay also were used. In this research, 7 severely affected foetuses were identified during PND including 3 foetuses with FXIII deficiency, 3 with FVII deficiency and 1 with FX deficiency. Out of these 7 cases, intrauterine ICH occurred in 1 case with FXIII deficiency, 1 was electively aborted and 1 case with severe FVII deficiency received intrauterine factor transfusion. Postdelivery ICH was reported for 1 patient with severe FVII deficiency within the first month of life. All other pregnancies were uneventful.

Factor VII Deficiency: Clinical Phenotype, Genotype and Therapy

Factor VII deficiency is the most common among rare inherited autosomal recessive bleeding disorders, and is a chameleon disease due to the lack of a direct correlation between plasma levels of coagulation Factor VII and bleeding manifestations. Clinical phenotypes range from asymptomatic condition—even in homozygous subjects—to severe life-threatening bleedings (central nervous system, gastrointestinal bleeding). Prediction of bleeding risk is thus based on multiple parameters that challenge disease management. Spontaneous or surgical bleedings require accurate treatment schedules, and patients at high risk of severe hemorrhages may need prophylaxis from childhood onwards. The aim of the current review is to depict an updated summary of clinical phenotype, laboratory diagnosis, and treatment of inherited Factor VII deficiency.

Factor VII Deficiency: From Basics to Clinical Laboratory Diagnosis and Patient Management

Factor VII (FVII) deficiency is a rare inheritable bleeding disorder affecting 1/500 000 individuals. Clinical manifestations are heterogeneous, from asymptomatic to severe and potentially fatal bleeding. These clinical manifestations do not correlate well with FVII plasma levels. For this reason, FVII-deficient patient management during surgery or for long-term prophylaxis remains challenging. Laboratory testing for FVII activity is, however, the first-line method for FVII deficiency diagnosis and is helpful for managing patients in combination with clinical history. Additional testing consists of FVII immunoassay and genetic testing. Genetic abnormalities on the FVII gene are heterogeneous and can translate into quantitative or qualitative defects. Some of the latter can react differently with different thromboplastins; this can be misleading for the laboratory as no consensus exists at present on an FVII deficiency diagnosis methodology. Indeed, no single test is able to predict accurately the bleeding risk. This review provides a broad picture of inherited and acquired FVII deficiency with a particular focus on laboratory diagnosis.

Coagulation disorders seen through the window of molecular biology

Coagulation disorders have been traditionally worked up by their clinical phenotypes and coagulation factor assays which are dependent on APTT- and PT-based techniques. Development of chromogenic substrates in the late seventies and early eighties allowed coagulation factors to be measured like enzymes. There was still a major lacuna in the understanding of the biology of different coagulation disorders. Modern molecular biology - which developed as an unique synthesis of biochemistry, immunology, cell biology, and genetics - allowed us to have a more comprehensive understanding of the pathobiology of many of these coagulation disorders. This overview presents several examples which show how we have enriched our understanding about the varied clinical phenotypes of different coagulation disorders.