What is combined deficiency of vitamin K-dependent clotting factors?
Inherited combined deficiency of the vitamin K-dependent clotting factors (VKCFD) is a very rare inherited bleeding disorder that is caused by a problem with clotting factors II, VII, IX, and X. In order to continue the chain reaction of the coagulation cascade, these four factors need to be activated in a chemical reaction that involves vitamin K. When this reaction does not happen the way it should, the clotting reaction is blocked and the blood clot does not form.
VKCFD is an autosomal recessive disorder, which means that both parents must carry the defective gene in order to pass it on to their child. It also means that the disorder affects both males and females. VKCFD is very rare, but like all autosomal recessive disorders, it is found more frequently in areas of the world where marriage between close relatives is common.
VKCFD can also be acquired later in life as a result of disorders of the bowel, liver disease, dietary vitamin K deficiency, or certain medications such as the blood-thinning drug Coumadin®. Acquired VKCFD is more common than the inherited form. Some newborn babies have a temporary vitamin K deficiency, which can be treated with supplements at birth.
The symptoms of VKCFD vary a great deal from one individual to another but are generally mild. The first symptoms may appear at birth or not until later in life. Symptoms at birth must be differentiated from the acquired deficiency. People with severe deficiencies can have serious bleeding episodes, but the more serious symptoms are generally rare and only occur in those individuals with very low factor levels.
- bleeding from the umbilical cord stump at birth
- bleeding into joints (hemarthrosis)
- bleeding in soft tissue and muscle
- bleeding in the gut (gastrointestinal hemorrhage)
- easy bruising
- excessive bleeding after surgery
- bleeding in the brain (intracranial hemorrhage)
- skeletal abnormalities and mild hearing loss (in severe cases)
VKCFD is diagnosed by a variety of blood tests that should be performed by a specialist at a haemophilia/bleeding disorders treatment centre. Care should be taken, particularly in newborns, to exclude causes of acquired vitamin K deficiency or exposure to certain medications.
There are three treatments available for VKCFD.
- Vitamin K
- Prothrombin complex concentrates (PCC)
- Fresh frozen plasma (FFP)