With local health authorities taking a generous approach to information sharing citing "common good" but more likely for administrative convenience (see Patients' privacy could be compromised by health b...), the opportunity to consider cases like the one presented will be swept aside.
As part of your treatment you need genetic analysis of predisposition towards several disease pathways. You are frightened that exposure of the results will a) reveal your mixed race heritage and b) prejudice your employability, insurability and sociability. So you agree with your consultant to test under an alias. And your treatment proceeds and you get on with your life.
Unbeknownst to you (does Beyonce have an evil twin called UnBeyonce?), your consultant also treats your child/children from a previous relationship, and recognizes that your genetic results are relevant to them. Your consultant knows that you would refuse to release your information, but their continued good health is dependent on having this information available. Just for the sake of preserving the moral dilemma, getting the genetic information from the children is not adequate, sufficient or practical (they live now in a foreign country, or something like that).
1. Is your right to control of information regarding your genetic history absolute?
2. Does your consultant have ethical responsibilities to act despite your desire for secrecy?
3. If sperm donors are required to disclose identity to their children, is a precedent established for requiring you to yield your genetic information?
4. Who should make the final decision?
My view ... 1. Yes ; 2. No, not outside the individual patient - carer relationship ; 3. Probably, in a legal sense. This is a bad thing! Genetic information is probably the ultimate in "identity" information; 4. The patient fully informed by consultant.