haemophilia Flashcards
define haemophilia
Haemophilia A and B are x-linked recessive bleeding disorders, caused by deficiencies of clotting factors VIII and IX, respectively.
what are the 2 types of haemophilia
A & B
which haemophilia is more common
A
what is haemophilia A caused by
a range of mutations within the factor VIII gene
70% of which are inherited
and the other 30% are spontaneous.
what is haemophilia B caused by
a single mutation of the factor IX gene.
inheritance pattern of haemophilia
x-linked recessive conditions and therefore are more common in men.
why are x linked recessive conditions more common in men
Men only have 1 X chromosome,
therefore only need a single mutation, but
women need a mutation on BOTH X
chromosomes to display symptoms.
when do patients usually present with haempophilia
Patients typically present in early life due to the condition’s inherited nature.
signs and symptoms of haemophilia
*. spontaneous bleeding into soft tissues
* Hemarthrosis (bleeding into the joints)
* Very easy bruising
* Excessively long/recurrent nose bleeds
investigations for haemophilia
- Factor VIII/IX Assay – DIAGNOSTIC
- blood tests
what do haemophilia blood tests show
*APTT is elevated
* vWF antigen is normal in type A
* Defective platelet function
when are most cases of haemophilia diagnosed
2/3 of severe haemophilia, is diagnosed at birth, as a parent is a known/suspected carrier.
when are other cases of haemophilia diagnosed
when the baby begins to
crawl or fall, or there is an eruption of
dentition (baby teeth coming through).
treatment for haemophilia A
IV prophylactic factor VIII and
desmopressin (releases factor VIII stored in vessel walls).
Desmopressin only can be used for minor bleeds.
acute treatment for haemophilia B
recombinant factor IX – (1st LINE)
If unavailable – fresh frozen plasma or
cryoprecipitate
