Address: Molecular genetics laboratory and counselling service, Centre for Haemostasis and Thrombosis, 1st floor, South Wing, St Thomas' Hospital, Westminster Bridge Road London SE1 7EH
Mike Mitchell – principal clinical scientist. Tel: 020 7188 2798
Jacky Cutler – chief biomedical scientist. Tel:020 7188 2798
Referral letters should be sent to the centre head of department and cases are discussed at regular meetings. For cases accepted by the service, an early appointment will be sent to the patient and the patient will be seen in the Haemophilia Reference Centre and jointly with other specialist professionals if required.
Patients registered with the Centre for Haemostasis and Thrombosis (the Haemophilia Reference Centre), whose diagnosis is known to the counsellors, can combine appointments providing that the counselling sheet is discussed. Daughters of carriers may undergo phenotypic analysis at any age. DNA analysis should be carried out at or following the age of consent i.e. 16 years of age.
CVS, at 11/12 weeks is the preferred option for pre-natal diagnosis, but the consultee should be fully informed of the implications of the diagnosis at this stage (e.g. termination of the pregnancy may have to be considered) and the risk of fetal loss.
Karyotypic and DNA analyses will be performed on the same sampling occasion to determine the sex of the foetus, and the underlying and genotypic information of relevance. This information should be offered to the mother/parents.
Any chromosomal abnormalities detected through karyotypic analyses should be referred to an appropriate specialist after discussion with the consultee. Scanning for foetal sex at 18/20 weeks is a non-invasive procedure, which can be offered if termination is not considered an appropriate option.
A medical file will be established for all patients referred for carrier testing through a clinician's letter. It is possible to obtain genetic information about other family members in the process of testing the consultee. All family members who wish to know their own results e.g. sisters, should also obtain a referral letter, so that hospital notes can be made up for them.
Genetic information obtained during the analysis is stored confidentially and shared only with the referring clinician. Consent is required from the patient before any information can be disclosed to any other party e.g. for determination of carrier status of diagnosis or other family members.
Confidentiality in all these issues must be respected at all times.