12. Hemophilia Flashcards
muscle hematomas or intracranial bleeding can occur how long after the original injury?
as much as 4 or 5 days
in severe hemophilia A, what is the most common symptom?
spontaneous joint or deep muscle bleeding
with moderate Hemophilia A, what is the general clinical picture?
seldom spontaneous bleeding; do ahve prolonged oozing after relatively minor trauma.
what is the clinical picture with mild hemophilia A?
no spontaneous bleeding but need prophy before surgery, tooth extraction, major injuries.
where are Factor 8 and 9 coded?
X chromosome. 99% of patients are male
normal factor 8 level?
50-150%
carrier females can have F8 level of what?
can be as low as mild F8 men: carriers are at risk for bleeding.
which coag screening test will be prolonged?
aPTT
what is the genetic abnormality associated with severe F8 deficiency?
Inversion mutation: F8 intron 22 recombines with upstream DNA.
accounts for half of cases of severe Hem A. F8 intron gene 1 inversion accounts for 2-3%. the other half of cases are gross gene alterations; large deletions or insertions, frameshifts.
what chromosome/arm is F8 located on?
long arm of the X chromosome
how is the diagnosis made for Hem A?
F8 clotting activity
why is molecular genetic testing done on a proband?
to detect the family-specific mutation, in order to counsel family members. also can help predict the clinical phenotype and risk of developing an inhibitor
how are the genetic mutations detected?
Southern Blot testing, PCR
what does F8 do?
cofactor for Vit-K dependent coag factors (prothrombin/2, 7, 9, 10, proteins C and S
