After consideration of her family tree you realise if there are no non-paternity issues she is an “obligate carrier” of Haemophillia A.
After counselling and discussion she agrees to having genetic testing for herself. She is willing to have free fetal DNA testing for fetal sex that can be carried out after 11 weeks. She also consents to checking her factor VIII level.
A discussion regarding the next steps for diagnosis if the fetus is a male occurs. The lady is not keen to undergo CVS due to miscarriage risk and is clear she would continue with the pregnancy regardless of the outcome.
She is otherwise well and all her booking bloods are satisfactory. Her bleeding history is unremarkable she has had a dental extraction a few years ago without complication and has not had any other bleeding.
You agree to review her in clinic with the results of the above tests.
What is the commonest mutation seen in Haemophillia A patients?
If the patient was keen for CVS for pre natal diagnostic testing what level of factor VIII would you aim for to minimise bleeding risks?
What treatment would you use if required to increase maternal factor VIII in preparation for CVS?