Genetics evidence revolution: How should courts determine permission applications?

There has been a revolution in genetic testing over the past decade. Technological advances have greatly increased the scope and use of testing. Testing is now faster and cheaper.

This has meant that it has become easier to analyse a whole, or large sections of a genome in detail[1]. This innovation brings with it ethical challenges, most notably in terms of consent and disclosure to other family members who may be affected by information identified[2].

These developments are beginning to ripple out to clinical negligence litigation. As they do, the courts will be asked to conduct a sensitive balancing exercise between the Claimant’s Article 8 rights and the Article 6 rights of the Defendant to defend himself.


When the Claimant was nine months old he suffered meningitis which sadly was not diagnosed when he attended A&E. By the time it was identified, the infection had passed into his brain. The Claimant says that this delay has caused him to sustain a profound neurological injury. The Defendant denies liability.

The case is made more complex because there is some evidence, albeit limited given the Claimant’s age at the time of injury, that he possibly had a pre-existing neurological impairment.

The Defendant wishes to investigate this congenital impairment through genetic testing. If an impairment is identified, it will seek to argue that either the delay caused no exacerbation of the Claimant’s pre-existing condition or that the index injury is divisible and therefore  will seek an apportionment of damages.

At a CMC last week the Defendant asked Master Cook for permission to rely on expert genetic evidence.

Approach to application for genetics evidence

Master Cook described the issue as “somewhat unusual and sensitive”. He was satisfied that the test under CPR 35.1 was met, namely that genetic evidence was reasonably required to resolve an issue in proceedings: causation. He was mindful, however, of the intrusive nature of genetic tests (they may require blood tests from both the Claimant and his mother, his father not being traceable); and that they may have ramifications for the Claimant and his wider family.

Genetic tests may generate unexpected, incidental findings, this is especially true of whole genome sequences, as opposed to a specific clinical test. Until the Defendant’s expert meets the Claimant, the Defendant could not state which tests were likely to be required.

Incidental findings may relate to other family members as they share genetic material. In this case the Claimant has an older sister who is 24. Genetic tests may highlight issues which will impact her future life (for example her plans to have children, and whether she is at greater risk of diseases particularly prevalent in women such breast cancer (BRCA1 and BRCA2 genes)).

Even if a person has a genetic condition, the decision whether to explore diagnosis should be theirs, or, where they are a protected party, the decision of the litigation friend. A diagnosis may entail painful information, such as a reduced life expectancy, which the person may rather not know.

Bearing in mind these important ethical concerns, Master Cook considered that although genetics evidence should be permitted, that did not mean that the full range of testing will be carried out.

Prior to the hearing, the parties had discussed a “Compromise Position” which the Master considered provided an appropriately careful approach.

The compromise position

The next stage will be that the Claimant and his mother will have an initial assessment by a clinical geneticist instructed by the Defendant. At the assessment, the expert will identify what tests are proposed and will provide the relevant consent information. If the Claimant through his mother consents, then testing will take place then and there. Otherwise, the Claimant will be given time to consider.

The Claimant will thereafter indicate whether he consents. If he objects then Directions specify a date by which the Defendant may make an application that unless the Claimant consents, the claim should be stayed. The Claimant also has an opportunity to respond, explaining why he objects. His objection will be made in light of the nature and extent of testing said to be required and having been informed of the risks and advantages of the test proposed.


Genetics evidence is likely to feature in an increasing number of claims, given the technological advances in testing. It may be relevant to a wide array of cases – neurological conditions, heart problems and cerebral palsy.[3]

A careful approach is required given the sensitive nature of such evidence. The staged approach above may be a useful starting point to consider in other cases.



[1] Royal College of Physicians, Royal College of Pathologists, British Society for Genetic Medicine, “Consent and confidentiality in genomic medicine: Guidance on the use of genetic and genomic information in the clinic”, 3rd ed., July 2019 at [1]

[2] An issue that was at the fore in ABC v St George’s Healthcare NHS Trust [2020] EWHC 455 (QB)

[3] In T v Imperial [2020] EWHC 1147 (QB) at [18] the Defendant’s expert commented that there is increasing evidence that “cerebral palsy” can be caused by genetic mutations.


John de Bono QC and Frances McClenaghan are instructed for the Claimant by Emma Wray of Hodge Jones & Allen