haemophillia B

Question 1

pathology

Answer 1

Mutation on X chromosome
-deficiency or non-functioning FIX

Question 2

M:F?

Answer 2

1:20k male
1:a milly female

Question 3

symptoms

Answer 3

carriers may show mild symptoms

Question 4

severity

Answer 4

Mild - FIX >5%
Moderate - FIX 1-5%
Severe – FIX<1%

Question 5

clinical presentation

Answer 5

Spontaneous bleeds if severe from early life – typically joint and muscle bleeds
Excessive bleeding after challenges – all types
Recurrent joint bleeds – haemophilic arthropathy ->disability

Question 6

investigations

Answer 6

Isolated prolonged APTT -> check FIX assay

Question 7

treatment

Answer 7

Factor IX replacement
-on demand if bleeding/surgery for mild/mod
-regular prophylaxis if severe