Factor VII deficiency of ... (Factor VII deficiency) - Gen F7
Factor VII deficiency, also known as proconvertin deficiency is an inherited bleeding disorder caused by a problem with factor VII. This disease may occur at a later stage of life, as a result of liver disease, vitamin K deficiency or consumption of certain anticoagulants.
Signs and symptoms of the disease can occur at any age, although the most serious cases are evident in childhood. These symptoms can be severe, including early onset of intracerebral haemorrhage, repeated hemarthrosis, recurrent epistaxis, menorrhagia and bleeding caused by surgery. Although factor VII deficiency is mainly associated with increased bleeding, some people with the disease suffer from thrombosis. It is estimated that about one - third of people with factor VII deficiency, does not show any bleeding problem.
The inherited form of factor VII deficiency, known as congenital factor VII deficiency is due to mutations in the F7 gene (coagulation factor VII), located on the long arm of chromosome 13 (13q34), encoding the clotting factor VII. This factor circulates in the blood in a zymogen form and becomes an active form by either IXa, Xa, XIIa, or thrombin by minor proteolysis factors. Upon activation of coagulation factor VII, a heavy chain containing a catalytic domain and a light chain containing EGF domains-2, and two chains are held together by a disulfide bond is generated. In the presence of calcium and factor III ions, activated factor active then, further, the coagulation cascade by converting factor IX into factor IXa and / or factor X to factor Xa.
They have identified at least 3,000 in the F7 gene mutations in people with factor VII deficiency. The mutations identified in the gene give rise to base pair substitutions, deletions and mutations binding splicing. Some mutations are identified A294V, A294V double / 11128delC in exon 8 at the carboxy terminus of the gene and ala244val mutation (A244V). Mutations in the gene cause F7 organism encodes factor VII less than or should give rise to a factor VII that does not function properly or is not functional. As a result, la reacción de coagulación is stopped prematurely and the blood clot is not formed.
Congenital deficiency of factor VII is inherited as an autosomal recessive pattern, that is, both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.
Tests in IVAMI: in IVAMI perform detection of mutations associated with factor VII deficiency, by complete PCR amplification of the exons of the F7 gene, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).