Hemophilia Chapter 10 Flashcards

Questions and Answers

What does the coagulation cascade chart represent?

A visual representation of all blood coagulation factors

A diagram showing coagulation pathways

A step-by-step flow of coagulation processes

All of the above (correct)

What mutation is associated with Hemophilia A?

F8 gene

What is the mode of inheritance for Hemophilia A?

X-linked recessive

What gene is mutated in Hemophilia B?

F9 gene Signup and view all the answers

What mode of inheritance exists for Hemophilia B?

X-linked recessive Signup and view all the answers

Define variable expressivity.

The expression of the disease is variable among those who are affected. Signup and view all the answers

Describe the clinical findings for severe Hemophilia.

Less than 1% normal factor activity with spontaneous joint and muscle bleeding. Signup and view all the answers

What are the initial lab findings for a F8 and F9 mutation?

Prolonged APTT, normal PT, normal bleeding time, normal fibrinogen levels. Signup and view all the answers

What joints are most commonly affected by severe hemophilia?

Knees, ankles, elbows Signup and view all the answers

What is a De novo mutation?

Mutations that occur for the first time in one family member and are not inherited. Signup and view all the answers

What does APTT measurement evaluate?

The intrinsic pathway of the coagulation cascade. Signup and view all the answers

What is the PT measurement used for?

Evaluate the extrinsic pathway Signup and view all the answers

Neither PT nor APTT can differentiate between factor deficiencies or the presence of specific factor inhibitors.

True Signup and view all the answers

Low to normal clotting activity in these screening tests completely rules out the presence of hemophilia A.

False Signup and view all the answers

What should all bleeding disorders be screened with?

APTT measurement, PT measurement, bleeding time measurement, platelet count. Signup and view all the answers

What can be done to increase the levels of factors 8 and 9?

Estrogens, oral contraceptives, epinephrine, desmopressin acetate, vigorous exercise. Signup and view all the answers

What is the best screening test for platelet function disorder?

Bleeding time. Signup and view all the answers

Mutations in mild to moderate hemophilia tend to be which type?

All of the above Signup and view all the answers

Hemophilia affected males will transmit the mutation to all their but to none of their .

daughters, sons Signup and view all the answers

Study Notes

Hemophilia Overview

Hemophilia is classified into two main types: Hemophilia A (mutation of the F8 gene) and Hemophilia B (mutation of the F9 gene).
Both types exhibit X-linked recessive inheritance patterns, primarily affecting males.

Hemophilia A

Caused by mutations in the F8 gene, leading to impaired production of coagulation Factor VIII.
Factor VIII is crucial for proper blood coagulation.
Severity classifications:
- Severe: < 1% normal factor activity; spontaneous joint and muscle bleeding occurs.
- Moderate: 1-5% normal factor activity; bleeding from minor trauma and postoperative.
- Mild: 5-40% normal factor activity; bleeding occurs post-operatively or after mild trauma, no spontaneous bleeding.

Hemophilia B

Caused by mutations in the F9 gene, resulting in insufficient levels of coagulation Factor IX.
Also characterized by X-linked recessive inheritance.

Variable Expressivity

Refers to the varying expression of disease symptoms among affected individuals, demonstrating different levels of severity.

Laboratory Findings

Initial lab findings for both Hemophilia A and B include:
- Prolonged activated partial thromboplastin time (APTT).
- Normal prothrombin time (PT), bleeding time, and fibrinogen levels.
APTT is part of the intrinsic pathway of the coagulation cascade.

Genetic Transmission

Hemophilia is not inherited from father to son because males transmit only Y chromosomes to male offspring.
Commonly affected joints in severe hemophilia include knees, ankles, and elbows.

De Novo Mutations

Alterations that occur for the first time in a family member, not inherited.
Key for understanding unique cases of hemophilia.

Screening and Monitoring

APTT is most sensitive for detecting moderate to severe hemophilia.
APTT is also useful for monitoring heparin therapy and detecting clotting inhibitors.
Prothrombin time (PT) measures the extrinsic pathway, useful for liver function and monitoring long-term anticoagulant therapy.

Testing and Counseling

Essential screenings for bleeding disorders include APTT, PT, bleeding time, and platelet count.
Specific coagulation factors are assessed based on initial screening results.

Management & Treatment

Treatments to increase levels of factors VIII and IX include:
- Hormonal treatments (estrogens, oral contraceptives).
- Epinephrine and desmopressin acetate, the latter enhancing factor VIII levels.
- Vigorous exercise can aid in management.

Platelet Function Testing

Bleeding time is the best screening test for platelet function disorders, prolonged in von Willebrand's disease and qualitative platelet disorders.

Mutation Types in Hemophilia

Mild to moderate disease often linked to point or missense mutations.
Severe disease typically associated with deletion mutations that respond poorly to therapy.
Males with hemophilia pass the mutation to all daughters but none of their sons.

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Description

Explore key concepts and definitions related to Hemophilia in this comprehensive flashcard quiz. Understand the coagulation cascade, mutations involved in Hemophilia A and B, and their inheritance patterns. Perfect for studying or reinforcing knowledge on this important topic.