Hemophilia A Overview

Study Notes

Hemophilia A Overview

Hemophilia A is a hereditary bleeding disorder caused by a deficiency in blood clotting factor VIII.
Insufficient factor VIII leads to improper coagulation and inability to control bleeding.

Causes

It is an inherited X-linked recessive trait, with the defective gene located on the X chromosome.
Males are predominantly affected due to having only one X chromosome; a defective gene on it results in hemophilia A.
Females can be carriers with one defective gene and can pass it to offspring.
Risk factors include a family history of bleeding disorders and male gender.

Symptoms

Symptoms vary in severity, with bleeding being the primary indicator.
Initial symptoms often manifest during infancy, especially during circumcision.
Internal bleeding can occur unpredictably, with other symptoms including:
- Joint bleeding causing pain and swelling
- Hematuria (blood in urine) or hematochezia (blood in stool)
- Bruising, nosebleeds, and prolonged bleeding from injuries or surgeries.
- Spontaneous bleeding may also occur.

Tests

Coagulation studies are necessary for diagnosing suspected bleeding disorders.
Key tests for hemophilia A include:
- Prothrombin time
- Bleeding time
- Fibrinogen levels
- Partial thromboplastin time (PTT)
- Serum factor VIII activity

Treatment

Treatment involves replacing the missing factor VIII, often through factor IX concentrates, dosed according to individual needs.
Mild cases may use desmopressin (DDAVP) to stimulate release of stored factor VIII.
Preventive treatment is crucial for severe cases, especially before surgeries or dental work.
Patients are advised to receive the hepatitis B vaccine due to increased risk associated with blood products.
Management may be necessary for those who develop inhibitors to factor VIII, potentially using factor VIIa for clotting.

Description

This quiz provides a comprehensive overview of Hemophilia A, a hereditary bleeding disorder. You will learn about its causes, symptoms, and how it affects individuals. Understand the genetic factors and inheritance patterns that contribute to this condition.