Hello and welcome to the zero to finals podcast.

My name is Tom and in this episode I'm going to be talking to you about hemophilia.

And you can find written notes on this topic at zero to finals.com slash hemophilia

or in the hematology section of the second edition of the zero definals medicine book.

So let's get straight into it.

Hemophilia A and hemophilia B are severe inherited bleeding disorders.

Hemophilia A is caused by deficiency of factor 8. Hemophilia B, which is also known as

Christmas disease, is caused by a deficiency in factor 9. Let's talk about ex-linked recessive

genetic inheritance. Hemophilia A and hemophilia B are both ex-linked recessive diseases.

All X-chromosones need to have the abnormal gene for the patient to have hemophilia.

Males only have one X-ch one X chromosome and require only one abnormal copy for them to have the

disease. Females have two X chromosomes, so when one copy is affected, they are asymptomatic

carriers of the gene because they still have the other normal X chromosome.

Therefore, hemophilia A and hemophilia B primarily affect males.

For a female to be affected, they would have to inherit two abnormal X chromosomes.

Therefore, they would require an affected father and a mother who is either a carrier

or affected herself. Let's talk about the features. Both hemophilia A and B are severe bleeding

disorders. Patients can bleed excessively in response to minor trauma and they're at risk of spontaneous

bleeding without any trauma. Most cases present in neonates or early childhood. It presents

with intracranial hemorrhage, hematomas and cord bleeding in neonates.

Spontaneous bleeding into joints, which is called hemarthrosis,

such as the ankle, knee or elbow, can lead to joint damage and deformity.

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