PEDBASE.org - The Pediatric Database - Detailed information of HEMOPHILIA B (CHRISTMAS DISEASE)

HEMOPHILIA B (CHRISTMAS DISEASE)

DEFINITION:

A coagulation disorder characterized by a deficiency in Factor IX resulting in a bleeding diathesis.

EPIDEMIOLOGY:

incidence: 1/40,000 (15-20% of Hemophilias)
age of onset:
- newborn (severe) -> childhood (mild)
risk factors:
- familial - x-linked recessive
  - chrom.#: Xq27.1-q27.2
  - gene: coagulation factor IX

PATHOGENESIS:

1. Background

Factor IX is a component of the Intrinsic Pathway and in its activated form (IXa), combines with Factor VIII and a phospholipid to activate Factor X within the Common Pathway - Steven Christmas (age 46) died on Dec. 22, 1993 of complications of AID's

2. Genetic Defect

genetic defect -> deficiency of Factor IX -> clinical severity related to the level of Factor IX:

1. Severe

Factor IX activity is < 1% of normal
onset of bleeding in the newborn period
- hematomas after injections or circumcision
- hemarthroses and deep tissue hemorrhages
bleeding may be spontaneous
clinical evidence of increased bleeding in 90% of these patients by 1 year of age

2. Moderate

Factor IX activity is 1-5% of normal
onset of bleeding during infancy
- excessive bruising with ambulation
- some arthrosis
bleeding may be spontaneous but usually following mild to moderate trauma

3. Mild

Factor IX activity is 5-20% of normal
onset of bleeding during childhood
bleeding is not spontaneous and follows moderate to severe trauma, dental work, or surgery

CLINICAL FEATURES:

1. Common Sites of Hemorrhage

1. Hemarthrosis

hallmark of Hemophilia
elbows, knees, and ankles
pain, swelling, limited range of motion of affected joint

2. Muscle Hematomas

pain, swelling, may produce muscle atrophy

3. Mucous Membranes

mouth, teeth, nose (epistaxis), gastrointestinal

4. Hemorrhage Causing Peripheral Nerve Lesions

femoral - iliopsoas muscle
sciatic - buttock
tibial - calf
perineal - anterior leg compartment
median and ulner - forearm flexors

5. High Risk Hemorrhages

intracranial, intraspinal
retropharyngeal
retroperitoneal

6. Hematuria

INVESTIGATIONS:

1. Serum

prolonged PTT
decreased Factor IX
normal PT, bleeding time, thrombin time, platelet count

MANAGEMENT:

1. Supportive

avoid trauma and anticoagulants (i.e., ASA)
pad crib and playpen
pressure and cold compresses to bleeding sites
immunize against hepatitis B

2. Replacement Therapy

Factor IX Concentrate
- 1 unit/kg IV raises Factor IX activity by 1-1.2% of normal
- risk of hepatitis B and C viruses
Fresh Frozen Plasma
- 1 unit of Factor IX/cc IV

Pediatric Database - HEMOPHILIA B (CHRISTMAS DISEASE)

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