Congenital afibrinogenemia is a rare inherited blood disorder in which the blood

Blood

Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 does not clot normally due to a lack of or a malfunction involving fibrinogen

Fibrinogen

Fibrinogen is a soluble plasma glycoprotein, synthesised by the liver, that is converted by thrombin into fibrin during blood coagulation. This is achieved through processes in the coagulation cascade that activate the zymogen prothrombin to the serine protease thrombin, which is responsible for...

, a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 necessary for coagulation

Coagulation

Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis, the cessation of blood loss from a damaged vessel, wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel...

.

Fibrinogen is also known as Factor I. Its lack is inherited in an autosomic recessive way. It can express itself with excessive bleeding since birth (bleeding from umbilical cord, easy bruising, bleeding after circumcision)

Diagnostic tests

When a problem of fibrinogen is suspected, the following tests can be ordered:

PT

PTT

Fibrinogen level in blood (total and clottable)

Reptilase time

Trombin time