Hemophilias - PowerPoint PPT Presentation

1 / 10
About This Presentation
Title:

Hemophilias

Description:

Symptoms: spontaneous bleeding into joints and muscles/prolonged bleeding after ... ( I.e., aren't confined to wheel chairs due to joint arthritis, can work, have ... – PowerPoint PPT presentation

Number of Views:210
Avg rating:3.0/5.0
Slides: 11
Provided by: ValuedGate1040
Category:

less

Transcript and Presenter's Notes

Title: Hemophilias


1
Hemophilias
  • AHMG Fall 2004
  • Juniata College

2
Hemophilia
  • Affects about 1/5000-1/10000 males worldwide
  • Hemophilias A and B are X-linked recessive
  • A and B are indistinguishable phenotypically
  • Symptoms spontaneous bleeding into joints and
    muscles/prolonged bleeding after accidents or
    surgery

3
Hemophilia
4
Hemophilia
  • Hemophilia A mutations in the gene encoding
    Factor VIII
  • Hemophilia B mutations in the gene encoding
    Factor IX.
  • Hemo. B is 1/5 as common as A, and is usually
    slightly less severe.

Bolton-Maggs and Pasi. The Lancet. 361
1801-1809, 2003.
5
Hemophilia
  • Factor VIII gene is longer (26 exons) than Factor
    IX gene (8 exons).
  • Factor VIII gene is on Xq28 factor IX gene is on
    Xq27.
  • Most severely affected have no Factor produced,
    mildly affected have malformed, dysfunctional
    protein produced.

Bolton-Maggs and Pasi. The Lancet. 361
1801-1809, 2003.
6
Hemophilia A
7
Hemophilia A
8
Hemophilia treatment
  • There is no cure for hemophilia.
  • Treatment
  • During a bleeding episode, give replacement
    Factor (VIII or XI) that is absent in the patient
  • Prophylaxis give hemophiliac boys replacement
    factor 2-3 times a week so that the factors
    there if an injury event or spontaneous bleeding
    occurs.
  • Expensive in the short-term, but these boys live
    a full life. (I.e., arent confined to wheel
    chairs due to joint arthritis, can work, have
    normal life-expectancy.)
  • 10-15 of patients treated with replacement
    factors develop inhibitor antibodies to the
    replacement factors, making treatment even more
    difficult.

9
Hemophilia treatment
  • Source of Factors VIII and IX
  • Until 1992 and 1999, respectively, sole source
    was purification from donated blood plasma.
  • Problem until 1985 blood wasnt screened for
    virus, so hemophiliacs contracted hepatitis B and
    C and HIV from these plasma products
  • Now, we have recombinant Factor VIII and Factor
    IX
  • Dont come from patients, so theres no viral
    contamination.

10
Hemophilia
  • Good candidate for gene therapy
  • Only a 1-2 increase in the amount of Factor able
    to be produced would be enough to bring relief to
    patient and for patient to live normal life.
  • Are several trial so far, but none successful
    yet
  • Cant get the gene to the tissue that needs it.
  • Cant get the gene to be expressed for as long as
    is necessary for relief of symptoms.
  • Toxicity
Write a Comment
User Comments (0)
About PowerShow.com