Duty to warn?

A recent case involving Huntington’s disease poses difficult questions regarding duty of care and a patient’s right to confidentiality

  • Date: 28 August 2017


DOES a legal duty of care begin and end with a patient or can it extend to a third party, such as a close family member? A case heard recently before the Court of Appeal has addressed this question – as well as the limits of patient confidentiality when in possible conflict with the best interests of others. The ultimate outcome of ABC v St George’s Healthcare NHS Trust and Others is still pending but the case could have some far-reaching implications, especially in the complex area of genetic risk.


In 2007 the father of the claimant in the case shot and killed his wife and was later convicted of manslaughter on grounds of diminished responsibility. He was sentenced to a hospital order under Section 37 of the Mental Health Act. In 2009 it was discovered that the patient was suffering from the neurodegenerative progressive condition, Huntington’s disease. A child of a parent with the disease has a 50 per cent chance of developing the condition.

Staff working for the defendants discussed with the patient on a number of occasions the possibility of informing his three daughters of the diagnosis. Each time he expressly refused so as not to distress them and, in the case of the claimant who at the time was pregnant, he feared she may have an abortion. She gave birth in April 2010 and in August that year was accidentally informed about her father’s diagnosis. Subsequent testing revealed she was also suffering from Huntington’s disease.

The claimant pursued a wrongful birth claim against the Trust arguing that, despite her father’s wishes and his right to confidentiality, she should have been informed of his diagnosis. Had this been done, she would have terminated the pregnancy rather than face the possibility of her child being dependent on a seriously ill parent, perhaps being orphaned and maybe inheriting the disease. In support of her case, the claimant referred to GMC guidance permitting disclosure where a patient’s refusal to consent to disclosure would leave others exposed to a risk so serious that it outweighed the patient’s and the public’s interest in maintaining confidentiality.

The defendants applied to have the case struck out, arguing that under existing law they did not owe a legal duty of care to the claimant as she was not a patient. They accepted that the first two limbs of the three-part legal test for duty of care were established, namely that the injury the claimant suffered was foreseeable and that the relationship between her and the defendants was sufficiently proximate. However, the argument focused on the third limb – was it "fair, just and reasonable" to impose a duty of care on the defendants? On that point a number of policy reasons against imposing a duty were put forward.

In striking out the case, the High Court judge, Mr Justice Nicol, ruled that it was not fair, just and reasonable to find that the defendant had a duty of care to the claimant, as there was no special relationship between the parties that could support this.


On appeal the decision was reversed and the claim reinstated. It was held that there was at least an arguable case that the existing law around who a clinician owes a duty of care to should be extended to include third parties. Key points from the judgement are:

Potential for conflicting duties for clinicians. The Court was of the view that this would not be made any worse – i.e. the threat of facing a claim by a patient if their information is released contrary to their express wishes versus the possibility of litigation from a third party. The professional guidance which the claimant referred to already raised the need for clinicians to consider conflicting interests and that in some circumstances the duty of confidentiality may have to be overridden on the basis of public interest to prevent harm.

Floodgates argument. The defendants argued that imposing a duty in such circumstances would lead to potential application to a wide variety of medical scenarios aside from those involving genetic conditions (e.g. a patient suffering from an STD, a contagious disease or a failed vasectomy). This was met with the response that "definite, reliable and critical medical information" is acquired by the clinician only in the field of clinical genetics, which often means that the third party should become a patient. These cases could be distinguished from other situations, thus limiting the occasions where the duty would apply.

Patient autonomy. One cannot overlook the strong trend in recent clinical negligence case authority to emphasise patient autonomy. It would arguably be irrational to emphasise the need to inform patients so that they may take their own decisions about treatment, yet at the same time depriving of any legal remedy identified individuals about whom a relevant doctor has specific information which should cause them to become patients.

Undermining trust. It was arguable as per the defendants’ case that a duty to disclose information to third parties could undermine trust and confidence in the medical profession, but the court questioned the degree to which such a loss of confidence might be affected by a common law duty of care to the third party.

In the end the Court of Appeal ruled that it was arguable that clinicians treating a patient with Huntington’s disease had a duty to disclose the diagnosis to the patient’s daughter despite the specific request of the patient not to do so. The court in following guidance from the GMC on confidentiality, as well as specific guidance on genetic testing from two Royal Colleges and the British Society for Human Genetics, allowed the claimant’s case to be reinstated for a trial to consider the existence of a duty of care to third parties.


It is important to appreciate that the Court of Appeal is stating no more than the fact that the claimant has an arguable case that a duty of care should be extended to a third party and therefore the case is to proceed to a trial. There is no change to the current public interest disclosure exercise which clinicians must perform if there are conflicting interests between parties.

The case can be seen as another example where, as with the Montgomery decision on consent, the law is catching up with medical guidance. The Court of Appeal specifically referred to existing professional guidance stating that: "The Human Genetics Commission, the Nuffield Council on Bioethics and the GMC have all expressed the view that the rule of confidentiality is not absolute. In special circumstances it may be justified to breach confidence where the aversion of harm by the disclosure substantially outweighs the patient’s claim to confidentiality."

It remains to be seen following the reinstated trial of this case if an actual legal duty is imposed, thereby potentially extending the scope of those who could argue that a doctor owes them a duty of care. There will be much debate about how far any such duty may erode the rights of the patient and the circumstances in which it may operate. Until then clinicians must continue to ensure:

  • existing professional guidance is followed
  • discussions are clearly documented
  • professional advice is sought where necessary.

Majid Hassan is a partner in the clinical law team at Capsticks Solicitors

This page was correct at the time of publication. Any guidance is intended as general guidance for members only. If you are a member and need specific advice relating to your own circumstances, please contact one of our advisers.

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