Valance, Sarah; Brain, Margaret --- "The appropriateness of genetic testing in cerebral palsy cases" [2016] PrecedentAULA 15; (2016) 133 Precedent 4

THE APPROPRIATENESS OF GENETIC TESTING IN CEREBRAL PALSY CASES

By Sarah Vallance and Margaret Brain

Recently, it has become more common in cerebral palsy cases for defendants to request that the plaintiff undergo genetic testing to investigate whether there is an alternative or additional cause for their condition.

This trend is anticipated to continue as medical researchers’ understanding of the genetic contribution to human disease develops. However, there are a number of significant medical, ethical and legal issues associated with genetic testing. Therefore, if a plaintiff is requested as part of the claims process to undergo genetic testing, practitioners should carefully consider whether it is appropriate for their client to agree to genetic testing, or whether the request should be refused.

CEREBRAL PALSY AND ITS CAUSES

Cerebral palsy is a descriptive clinical term applied to a heterogeneous group of neurodevelopmental disorders characterised by a disorder of movement and posture, which are caused by a non-progressive but permanent insult to the developing foetal or infant brain.^[1] Cerebral palsy can be categorised in various ways, including the way it affects an individual’s movement (spastic, ataxic, dyskinetic or mixed); the part of the body which is affected (quadriplegic, hemiplegic or diplegic); and the severity of the impairments ,using the gross motor function classification system (GMFCS), the manual ability classification system (MACS) or the communication function classification system (CFCS).^[2] Cerebral palsy is often associated with other co-morbidities, such as intellectual impairments, speech and language deficits, visual impairments, hearing impairments and seizure disorders.^[3]

In the majority of individuals diagnosed with cerebral palsy, the specific cause of their cerebral palsy is unknown.^[4] However, a number of risk factors for cerebral palsy have been identified, including preterm delivery, intrauterine growth retardation, intrauterine infection, antepartum haemorrhage and hypoxic ischaemic insults in the antenatal or neonatal period.^[5] In addition, a genetic contribution to cerebral palsy has long been suspected, following studies of twins and persons with cerebral palsy in consanguineous families.^[6] However, routine genetic studies are not yet recommended in the diagnostic assessment of children with cerebral palsy.^[7] Therefore, the studies to date have generally focused on selected patient populations with positive family history, dysmorphic features or atypical clinical features, such as normal brain imaging.^[8]

Because cerebral palsy is a descriptive term rather than a clinical diagnosis, an individual could be diagnosed with cerebral palsy when in fact their condition is being caused or contributed to by an undiagnosed genetic condition. As our understanding of the genetic contribution to human disease increases, it is possible that genetic testing may become routine practice for individuals who have been given a diagnosis of cerebral palsy to determine whether there is a genetic cause for their condition. This is particularly likely if further scientific developments result in the identification of genetic conditions that can be treated or cured.

GENETIC TESTING

Genetic testing is used to identify changes in chromosomes, genes or proteins.^[9] Different tests are used depending on whether an individual’s chromosomes, genes or proteins are being examined, and more than 1,000 genetic tests are currently available in Australian and New Zealand laboratories.^[10] Tissues tested include blood, skin, saliva, hair follicles and cerebrospinal fluid.^[11]

Although it is outside the scope of this article to consider in detail the medical, ethical and legal issues that can arise with genetic testing, practitioners should be aware that there are a number of potential issues, including:

1. The impact that testing may have on an individual if a variant in a particular gene is discovered but the severity of the condition or the age at which the individual will start experiencing symptoms are unknown;

2. The impact that testing may have on an individual if a variant in a particular gene is discovered and the condition will ultimately be fatal for that individual;

3. The limits of testing if a variant or mutation of a gene is of unknown significance;

4. The potential for discrimination if testing reveals a variant; and

5. Whether an individual’s test results need to be disclosed to other family members if those results reveal genetic conditions that may impact on the health of other family members.

GENETIC TESTING IN CEREBRAL PALSY CLAIMS

For a small number of individuals with cerebral palsy, litigation may be pursued on the basis that deficiencies in that individual’s medical care have resulted in brain injury causing cerebral palsy. The most common example is where there are signs of foetal distress but the delivery of the foetus is delayed, resulting in a hypoxic ischaemic brain injury. Other examples include delays in diagnosis and treatment of medical conditions following delivery, such as herpes simplex encephalitis or hypoglycaemia.

As there are many possible causes of cerebral palsy, causation in cases involving cerebral palsy are usually complex and highly contested. In addition, due to the level of disability often associated with cerebral palsy, the damages being sought by plaintiffs are usually significant, amounting to millions of dollars. A defendant is entitled to take reasonable steps to ensure that issues which may bear upon the outcome of the proceedings are properly investigated. It is therefore not surprising that with the advances in medical research in understanding the genetic contribution to human disease, defendants are increasingly requesting plaintiffs to undergo genetic testing to determine whether there is an alternative or additional cause for the plaintiff’s condition.

If a defendant requests a plaintiff to undergo genetic testing, the following information should first be requested from the defendant so that the plaintiff can assess whether it is appropriate to agree to the tests:

1. what specific tests will be required;

2. the purpose of the tests being requested;

3. how the proposed tests will be conducted – that is, the taking of blood, urine, tissue or cerebrospinal fluid samples; and

4. whether the proposed pathologist/laboratory will require a medical referral and whether the plaintiff and their family will be required to undergo genetic counselling prior to and/or after the tests are performed.

After receiving this information, the practitioner should carefully consider a number of issues, including whether there are uncertainties as to the cause of the plaintiff’s injury, the appropriateness of the proposed tests, whether the tests will be invasive and could pose a serious threat to the plaintiff’s health, whether there have been unacceptable delays in requesting the tests and whether the court has the power to order testing if a request is refused and an application is then filed by the defendant.

Alternative or additional cause for plaintiff’s injury

The first issue to consider is whether there is sufficient evidence that the proposed testing has the capacity to throw light on the issues in the proceeding. If the request for testing is merely a ‘fishing expedition’, it is unlikely that a court will order the proposed testing. However, if significant causation issues have arisen in the proceeding and there is expert evidence suggesting that there may be an alternative or additional cause for the plaintiff’s condition, it is unlikely that a court will refuse a defendant’s request for testing.

In KF (by her tutor RF) v Royal Alexandra Hospital for Children^[12] (KF), the plaintiff alleged that there was a six-week delay in diagnosing and treating her hypoglycaemia, which resulted in serious brain damage. The defendants requested that the plaintiff undergo certain genetic tests to determine whether the plaintiff suffered from genomic disorders which may explain her developmental and language disorder. A number of experts had questioned whether another explanation may exist for the plaintiff’s developmental delay and, in particular, her verbal expressive disorder. As a result, the court ordered the plaintiff to submit to a blood test for the purpose of genetic testing.

In Plowman v Sisters of St John of God Inc^[13] (Plowman), the defendant sought an order that the plaintiff have a blood test for the purpose of undertaking comparative genomic hybridisation (CGH) testing. In that case, there was expert evidence that the plaintiff’s mild cerebral palsy and mild to moderate intellectual impairment were due to birth asphyxia. The damages claimed largely related to the plaintiff’s intellectual disability. The defendant obtained a report from a paediatric neurologist who expressed the view that the plaintiff’s clinical picture was probably attributable to the events which occurred during her delivery and the findings were probably due to hypoxic ischaemic brain damage suffered at that time. However, there were some slightly unusual features in that the plaintiff had a more clinically localised form of cerebral palsy but with substantial intellectual deficit. There was evidence that the proposed testing could provide an alternative explanation for the plaintiff’s intellectual disability. As a result, the court ordered the plaintiff to undergo the proposed tests.

In Zraika (by his tutor Zraika) v Walsh^[14] (Zraika), the plaintiff was involved in a motor vehicle accident while in utero. Shortly after he was born, he was diagnosed with microcephaly and developmental delay. A number of expert reports were obtained and it was apparent that there was a serious issue concerning the cause of the plaintiff’s brain injury, with one explanation for the injuries being a genetic cause. As a result, the court ordered the plaintiff to undergo the proposed tests.

As can be demonstrated by these cases, if a plaintiff presents with atypical features that are inconsistent with the alleged cause of the injury, it is likely that an order for genetic testing will be made by the court.

Scope of proposed tests

If expert evidence suggests that there may be an alternative or additional cause for the plaintiff’s condition, a practitioner should then consider whether the tests proposed by the defendant are appropriate to shed light on the issue in question. Given the variety of tests currently available, practitioners should liaise with the appropriate medical experts to determine the suitability of the proposed tests. As demonstrated in the case of KF,^[15] the courts will be more likely to order a plaintiff to submit to blood tests for genetic testing if the proposed tests are limited in their scope.

Invasiveness of tests

One of the factors that should be considered is whether the proposed tests are invasive and could pose a significant risk to the plaintiff’s health. A number of genetic tests involve the drawing of a small quantity of blood from a person’s vein. Although a blood test is invasive and has some risks, it is unlikely that an order for genetic testing will be refused on this basis, as it is a very common medical procedure. However, if the test will require more invasive methods, such as a lumbar puncture, a practitioner should liaise with their medical experts to determine whether the proposed tests pose a significant risk to the plaintiff’s health.

In the case of Plowman,^[16] one of the factors considered by the court was whether the plaintiff’s anxieties in relation to having medical treatment and her needle phobia should result in the defendant’s request for genetic testing to be declined. The court noted that the plaintiff had previously had an MRI scan performed under general anaesthetic. A single dose of Temazepam had been given in advance of the anaesthetic, which had prevented the plaintiff from experiencing any distress in relation to that procedure. The court also noted that the plaintiff had had a number of immunisations in the past. As a result, the court found that the plaintiff’s needle phobia on its own was not sufficient to prevent the court from making the order for testing.

Delays

In a number of cases, the plaintiffs have argued that genetic testing should be refused on the basis that there has been delay by the defendant(s) in requesting that the plaintiff undergo those tests.

In KF, the plaintiff argued that they should not be ordered to undergo genetic testing, as the proceedings had been ongoing for eight years. Although the court noted that the Civil Procedure Act 2005 (NSW) required litigants to ‘move with appropriate despatch in identifying the real issues in proceedings to facilitate the determination by the court of the case’, it did not consider the provisions should operate so that the second defendant was prevented from seeking genetic testing, as the objects of case management also included the just determination of the proceedings.^[17] However, the court said that the position could have been different if a very late application had been made after a trial date had been fixed.^[18]

However, in Zraika, an application for genetic testing was made after a hearing date had been fixed; genetic testing at that stage would inevitably result in the vacating of that date. The court noted that there had been some delays by the defendants, but as causation was such a serious issue, it would not be fair on the defendants to refuse to allow them to explore the issue, even though this would incur further delays.^[19]

A plaintiff is therefore unlikely to succeed in resisting an order for genetic testing on the basis of delay alone. The reason for this is that issues of causation in these types of cases are usually complex, the damages sought are invariably high and the defendant is likely to be greatly prejudiced if they are unable to explore these issues when question marks have been raised by experts about the cause of the plaintiff’s injury and consequent disabilities. In order for a request for genetic testing to be refused by a court, a plaintiff would have to show that there would be negative consequences to the plaintiff caused by the further delay, which would outweigh any negative consequences to the defendant.

Power of court to order testing

If a defendant requests a plaintiff to submit to genetic testing, the plaintiff’s practitioner should consider whether a court has the power to order testing if the request is declined and an interlocutory application is then filed. The rules in each jurisdiction differ and practitioners therefore need to be familiar with the legislation and case law applicable to their jurisdiction.

Some genetic tests require family members to be tested so that familial comparisons can be made. If a defendant requests family members to be tested, a plaintiff should consider whether this is appropriate and whether the court has the power to order non-parties to the proceedings to submit to blood tests. In Zraika, the plaintiff’s parents were ordered to undergo testing in addition to the plaintiff. However, it does not appear that the plaintiff’s parents objected to those orders being made.^[20]

CONCLUSION

As advances are made in medical research into the understanding of the genetic contribution to human disease, it is increasingly likely that defendants will request plaintiffs in cerebral palsy claims to undergo genetic testing. As there are a number of medical, ethical and legal issues that can arise with genetic testing, practitioners should not recommend that their clients undergo testing unless it is appropriate. The cases to date suggest that unless there is expert medical evidence which indicates that there may be an alternative or additional cause for the plaintiff’s medical condition, a plaintiff will not be ordered to undergo testing. If the cause of the cerebral palsy is in dispute and there is expert medical evidence suggesting that there may be an alternative or additional cause for the plaintiff’s condition, it is unlikely that a plaintiff will succeed in refusing a request for genetic testing in a subsequent application if the court has the power to order such testing and the proposed testing is limited in its scope. However, it is incumbent on the plaintiff’s practitioner to consider carefully each request on a case-by-case basis, as there are likely to be significant developments in the genetic contribution to human disease in the years ahead.

Sarah Vallance is an Associate with Maurice Blackburn Lawyers, Brisbane and practises exclusively in medical law. She is a Queensland accredited specialist in personal injuries. PHONE [phone] EMAIL [e-mail].

Margaret Brain is Special Counsel with Maurice Blackburn Lawyers, Brisbane and has more than 30 years’ experience in medical law. PHONE [phone] EMAIL [e-mail].

The authors would like to thank Ms Chloe Heterick, law student for her assistance with research for this article.

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^[1] Jane Leonard, Alison Cozens, Susan Reid, Michael Fahey, Michael Ditchfield and Dinah Reddihough, ‘Should children with cerebral palsy and normal imaging undergo testing for inherited metabolic disorders?’ (2011) 53 Developmental Medicine & Child Neurology 226.

^[2] Andres Moreno-de-Luca, David Ledbetter and Christa Martin, ‘Genomic insights into the etiology and classification of the cerebral palsies’ (2012) 11(3) Lancet Neurology, 283-92.

^[3] Ibid.

^[4] Ibid.

^[5] Karin Nelson, ‘Causative factors in cerebral palsy’ (2008) 51(4) Clinical Obstetrics and Gynecology, 749-62.

^[6] Moreno-de-Luca, above n 2.

^[7] Leonard, above n 1.

^[8] Maryam Oskoui, Matthew Gazzellone, Bhooma Thiruvahindrapuram, Mehdi Zarrei, John Andersen, John Wei, Zhuoshi Wang, Richard Wintle, Christian Marshall, Ronald Cohn, Rosanna Weksberg, Dimitri Stabropoulos, Darcy Fehlings, Michael Shevell and Stephen Scherer, ‘Clinically relevant copy number variations detected in cerebral palsy’ (2015) 6 Nature Communications, 7949 www.nature.com/naturecommunications.

^[9] NSW Government, ‘Genetic testing services’ (2015) t <http://www.genetics.edu.au/Genetics-Services/genetic-testing-services> .

^[10] The Royal College of Pathologists of Australasia, ‘RCPA Catalogue of Genetic Tests and Laboratories’ (2015) <http://genetictesting.rcpa.edu.au> .

^[11]NSW Government, above n 9.

^[12] [2010] NSWSC 891 (10 August 2010).

^[13] [2014] NSWSC 333 (28 March 2014).

^[14] [2014] NSWSC 1774 (16 December 2014, unreported).

^[15] Above n 12, [61]-[63].

^[16] Above, n 13, [80]-[82].

^[17] The overriding purpose is contained in s56 of the CPA. However, the court did not use the exact wording from that section in its judgment. The other relevant sections are ss57-60,

^[18] Above, n 12, [52].

^[19] Above, n 14, [49].

^[20] Ibid.

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