Can a disease injury aggravate a genetic predisposition?

In the matter of Booth v Fourmeninapub Pty Ltd [2020] NSWCA 57 the Court of Appeal was required to consider, amongst other things, whether a predisposition to a condition can satisfy either of the two limbs for a disease injury in s4(b)(i) and (ii) of the Workers Compensation Act 1987 (the 1987 Act).


The worker was employed at a hotel.  As a result of witnessing traumatic incidents during the course of her employment at the hotel, the worker suffered a psychological injury by way of a post traumatic stress disorder.  Two years after her injury, the worker’s Bipolar Disorder manifested. 

In April 2018, the worker made a claim for lump sum compensation, including for a Bipolar Disorder.  The worker relied on a report from Dr Scurrah.  Dr Scurrah made no deductions for pre-existing conditions as she was psychiatrically well prior to her injury.  Dr Scurrah said the worker’s Bipolar Disorder was not a pre-existing condition.  In his opinion, the worker’s Bipolar Disorder had developed as a result of treatment for depression with antidepressant medication.

The insurer disputed the worker’s claim on matters not relevant to the appeal.

In July 2018, the worker submitted a further claim for lump sum compensation.  In support of her claim, the worker relied upon a further report from Dr Scurrah.  In Dr Scurrah’s opinion as a consequence of treatment for the worker’s injury, it had aggravated, accelerated and/or exacerbated her underlying disease condition by way of Bipolar Disorder.  The question and answer were formulated in the form of a disease injury in s4(b)(ii) of the 1987 Act.

The insurer again disputed liability for the worker’s claim.  Part of the denial of liability was on the basis that it was not possible to aggravate, accelerate and/or exacerbate a condition which did not exist at the time.

Arbitrator’s decision

The worker commenced proceedings in the Workers Compensation Commission.  The matter proceeded to a contested hearing.  In the proceedings it was not disputed whether the worker had a genetic predisposition to Bipolar Disorder.  Arbitrator Edwards found the worker’s Bipolar Disorder was a disease and her employment was a substantial contributing factor to the aggravation, acceleration, exacerbation or deterioration of the disease within the meaning of s4(b)(ii) of the 1987 Act.

Presidential appeal

The employer appealed Arbitrator Edwards’ decision.  On appeal, President Phillips observed that Arbitrator Edwards had not been taken to any evidence that the worker had a pre-existing condition at the time of her work injury.  The evidence he was taken to, established that the worker had a predisposition to a genetic condition by way of Bipolar Disorder.

President Phillips held it was not open to the Arbitrator to find the worker had suffered a s4(b)(ii) injury.  He found the evidence merely established that the worker had a genetic predisposition to Bipolar Disorder and that was insufficient to establish a s4(b)(ii) injury had occurred.

Appeal to the Court of Appeal   

The worker appealed to the Court of Appeal on three grounds:

  1. President Phillips erred in failing to give effect to uncontradicted expert opinion that for the purposes of s4(b)(ii) of the 1987 Act, the worker suffered from an underlying disease condition by way of Bipolar Disorder.

  2. President Phillips erred in finding that, under s4(b)(ii) of the 1987 Act, the same legal conclusions applying to a worker with a ‘predisposition to a disease’ apply to a worker with a ‘genetic predisposition’.

  3. President Phillips erred in finding that a ‘genetic predisposition’ was not a ‘disease’ within the meaning of s4(b)(ii) of the 1987 Act.

In support of her appeal, the worker sought to rely upon fresh evidence by way of a report from Dr Maclean, a clinical geneticist.  The thrust of his evidence was that a “genetic disposition” is a latent susceptibility which was capable of being aggravated, accelerated, exacerbated or deteriorated.

The Court of Appeal refused to allow the report from Dr Maclean into evidence as it could have been obtained beforehand with reasonable diligence and his opinion would not alter the outcome of the appeal.

In dismissing the appeal, the Court of Appeal held:

  • President Phillips correctly construed the report of Dr Scurrah. Dr Scurrah’s report did not support the conclusion that a genetic predisposition was a disease.  The report from Dr Scurrah was directed to the possibility that the work incident or its consequences led to the development of Bipolar Disorder in circumstances where the worker was genetically predisposed to that condition.

  • The definition of “injury” in s4(b) of the 1987 Act contains two limbs which are distinct. Where the first limb applies (s4(b)(i)), the worker will not previously have had the relevant disease before their employment commenced.  Where the second limb applies (s4(b)(ii)), the worker will previously have had the disease, but their employment contributed (or was the main contributing factor) to an aggravation, acceleration, exacerbation or deterioration of the disease.

  • A predisposition simply means there is a future potential for a person to suffer from a condition. The fact that they are more likely to eventually suffer that condition does not mean they have the disease.  A genetic predisposition is not an abnormal physical or mental condition such as to constitute a “disease”.

In practice

A genetic predisposition cannot satisfy the test of a disease injury in s4(b)(i) or (ii) of the 1987 Act.  This is because:

  • A genetic predisposition is a condition which exists from birth and cannot satisfy a disease which was contracted in the course of their employment for the purpose of s4(b)(i) of the 1987 Act.

  • As a genetic predisposition exists from birth, it cannot be a disease for the purpose of s4(b)(ii) as there was no condition that had manifested that could be aggravated, accelerated, exacerbated or the subject of deterioration. While there is an increased likelihood the person may develop the condition, the person’s genes do not change after the condition has developed.  This is because there was no disease, as opposed to the mere disposition to the disease.

When dealing with disease injuries, it is critical to examine what the worker’s injury is, and any subsequent or change in diagnosis, and consider whether the worker suffered from a genetic predisposition to the disorder.  This is probably more relevant when dealing with cases involving cancers, hematologic disorders, cardiovascular disease and psychological disorders.

If there is a suggestion that the worker’s condition is a genetic predisposition, an appropriate expert will need to be qualified to an opinion on that point. 

Author: Stephen Marsh