Predictive Testing for Huntington’s Disease in Australia

Predictive testing for Huntington’s: the decision, and the law that just changed

Roughly 9,000 Australians have a parent with Huntington’s disease and therefore a 50 per cent chance of carrying the gene. Most of them have never been tested.

For decades, one of the main reasons was insurance. A predictive test result had to be disclosed when applying for life, trauma, total and permanent disability or income protection cover, and a positive result for a condition with the near-certainty of Huntington’s effectively ended the possibility of being insured. So people at risk faced a choice between knowing and being insurable — and a great many chose not to know, or arranged their insurance first and tested afterwards, or tested and told nobody.

That changed on 8 October 2026.

Australia now prohibits life insurers from soliciting or using adverse genetic test results in underwriting. The prohibition was legislated in April 2026 as an amendment to the Insurance Contracts Act, inserting section 33H, with a strict liability offence of around $19,800 and a civil penalty of up to approximately $1.65 million. It covers death cover, total and permanent disability, trauma and income protection. The Australian Medical Association welcomed it; international commentary noted it could unlock population genetic screening.

For the Huntington’s community specifically, this is the most significant Australian policy change in a generation, and it is three weeks old at the time of writing. Most published Australian material about HD and insurance predates it and is now wrong.

This guide sets out exactly what the ban does and does not cover, then covers the testing process itself, the decision, what happens afterwards, and the forms of testing that exist for people who do not want to know their own result.

What the insurance ban actually covers

Precision matters here, because the gaps are as important as the protection.

What is now prohibited. Life insurers may not ask for, or use, adverse genetic test results when deciding whether to offer cover, at what price, or on what terms. This applies to death, total and permanent disability, trauma and income protection products.

You may still volunteer a result, in writing, and an insurer may use a volunteered result only where doing so would not disadvantage the offer or the policy terms. In other words, a favourable result can help you; an unfavourable one cannot be held against you.

What insurers can still use. This is the part that matters most for Huntington’s:

• Existing diseases, and signs or symptoms of a possible disease. A clinical diagnosis of Huntington’s disease is not protected genetic information; it is a diagnosis, and insurers can consider it.
• Family medical history. An affected parent remains disclosable and usable.

So the protection is specific: it covers the predictive test result in a person who is currently well. It does not make Huntington’s invisible to insurers. Somebody with a parent who has HD will still be assessed on that family history, with or without a test. What the law removes is the additional penalty for having found out.

Health insurance was never affected, because Australian private health insurance is community-rated and genetic information cannot be used in it at all.

Timing. The ban applies to new policies commencing on or after 8 October 2026, and to existing policies varied on or after that date. It is not retrospective. People already carrying loadings or exclusions from an earlier disclosure continue to carry them unless they negotiate new cover — which is now worth doing, and is a conversation to have with a financial adviser or an insurance broker rather than assuming.

What this means practically for somebody at risk of HD. The insurance reason for not testing has largely gone. It has not entirely gone, because family history remains usable, so the sequencing of insurance applications still deserves thought. But the specific trap — that the act of finding out would itself destroy your insurability — no longer exists in Australian law.

And one caution. Superannuation-based insurance, group cover through an employer, and cover written overseas may sit under different arrangements. If insurance is a significant factor in your decision, get specific advice about your own policies rather than relying on a general rule, including this one.

What predictive testing is

Predictive testing, sometimes called presymptomatic testing, is a genetic test in a person who has no symptoms, to determine whether they carry the expanded gene. It is distinct from diagnostic testing, which is done in somebody who already has symptoms to confirm what is causing them.

Who can have it. An adult, aged 18 or over, with a blood relative diagnosed with Huntington’s disease. In New South Wales it is available only through a genetic counselling service, and the same model operates across Australia — this is not a test a GP orders and not a test available through a direct-to-consumer kit in any responsible form.

It is free through public genetic services in every state and territory.

What it tells you. Whether you carry an expanded CAG repeat, and how long the repeat is. Above 40 repeats, you will almost certainly develop Huntington’s within a normal lifespan. Between 36 and 39, you may develop it, possibly late or mildly, possibly not at all. Below 36, you will not develop it and cannot pass it on.

What it does not tell you. When. The Centre for Genetics Education states the position directly: the test cannot predict when symptoms will start or how severe they will be. Repeat length is associated with age at onset at a population level and is close to useless as an individual prediction in the common range. See Huntington’s genetics and the 50 per cent.

This is the single most important thing to grasp before deciding. A positive result does not hand you a date. It hands you a certainty without a schedule, which some people find more bearable than uncertainty and some find considerably less.

The process, step by step

Australian practice follows a protocol that has been in place in some form since the test became available in the late 1980s, and it is deliberately slow.

Referral. Through a GP, neurologist or HD service to a state genetic service, or by contacting the service directly in some states. Huntington’s Australia on 1800 244 735 can point you to the right one.

First appointment. Usually with a genetic counsellor, sometimes with a clinical geneticist. This appointment is not about taking blood. It covers the family history in detail, what the test can and cannot tell you, what each possible result would mean, how you think you would respond to each, who else would be affected by the information, and what supports you have. It frequently covers why you want to know now, which is a more useful question than it sounds.

Often a second appointment, and sometimes a neurological examination to establish whether any symptoms are already present — which, if they are, changes the test from predictive to diagnostic and changes everything downstream.

A deliberate gap. The protocol builds in time between counselling and testing, because the decision frequently looks different a month later. Published international recommendations and Australian practice both support this. Some people stop at this point, which is a successful outcome of the process rather than a failure of it.

The blood sample.

The results appointment, typically around three months later. In person, in a dedicated appointment, with a support person if you want one. Results are not given over the phone and not given by letter.

And the choice not to receive the result. You can withdraw at any point, including after the blood has been taken. The sample can be stored. Some people test, decide they do not want to know, and leave it. This is explicitly allowed for and it is not unusual.

Follow-up afterwards, whatever the result. This matters for both outcomes, for reasons covered below.

Confidentiality. Results are not released without the person’s written consent, except where a court requires them.

Who tests, and who does not

Uptake is much lower than most people assume. Australian research into predictive testing programmes going back to the late 1980s has found that only a minority of eligible at-risk people come forward, and the Australian literature has specifically examined the difficulty of measuring uptake accurately because the at-risk denominator is itself unknown.

The reasons people test, from the published and clinical experience:

Reproductive decisions. By far the most common reason, and the one with the clearest practical payoff, because a negative result removes the question entirely and a positive one opens the reproductive options described in the genetics guide.

Planning — career, finances, where to live, whether to take the promotion that means a mortgage.

Relief from uncertainty. A considerable number of people describe decades of monitoring themselves for symptoms, interpreting every dropped cup and every bad mood as the beginning, and find that unbearable.

Because a partner or a child wants to know.

And because the person has quietly concluded they already have it, and wants confirmation.

The reasons people do not test:

They do not want to know. This is a complete and sufficient reason and it deserves to be treated as one rather than as avoidance. Many people live full lives at 50 per cent risk.

Insurance — historically the dominant practical reason, and now substantially reduced.

Fear of what it would do to them, which is realistic, and which the counselling process is designed to explore.

Fear of what it would do to their family, including the fact that their own result reveals information about parents and siblings.

Employment concerns. The Disability Discrimination Act protects against discrimination on the basis of a disability a person may have in the future, and that protection is real, but enforcement is after the fact and people reasonably weigh that.

Or because knowing would change nothing they can act on, there being no treatment.

There is no right answer here and anybody suggesting otherwise should be disregarded. The one thing worth saying is that the decision is reversible in one direction only.

Afterwards: both results are harder than expected

The research on post-test outcomes contains a finding that people rarely anticipate.

A positive result is, as expected, extremely difficult, and the period around receiving it is one of elevated risk. GeneReviews notes that suicide and suicidal ideation are common in Huntington’s disease and that risk peaks around the time of diagnosis and when people lose independence. This is precisely why Australian protocol requires a dedicated results appointment with a support person and structured follow-up, rather than a phone call. If you are going through this, the follow-up is not a formality — use it. Lifeline is on 13 11 14, and Huntington’s Australia on 1800 244 735 can connect you with people who have been through the same appointment.

A negative result is harder than people expect, and this surprises nearly everybody. Reactions reported in the literature and in clinic include guilt at having escaped when siblings did not, a loss of identity for somebody who has organised their life around being at risk, grief that arrives belatedly for the affected parent, difficulty in relationships with affected siblings, and a flat anticlimax where elation was anticipated. Some people describe the year after a negative result as the hardest of their lives.

Both of these are reasons the follow-up exists. Both are reasons to tell at least one person before you go to the appointment, so that whatever the answer is, you are not carrying it home alone.

For people who do not want to know their own status

Two options exist and they are not widely known.

Exclusion testing in embryos. Through preimplantation genetic testing, embryos can be tested for which grandparental chromosome 4 they carry, and only those carrying the unaffected grandparent’s copy are transferred. The at-risk parent’s own status is never determined. This permits reproductive choice without a personal result. It is technically available in Australia through fertility services, it is emotionally and ethically complex, and it requires specialist counselling.

DNA banking. A sample is stored for future testing — by the person later, or in some circumstances for the benefit of relatives. The Centre for Genetics Education notes that some relatives want testing without learning their own result, and that DNA banking is an option. This is particularly relevant where an affected family member is unwell and their sample would be informative for the wider family after their death.

And for a person whose own parent’s status is unknown, an unaffected parent’s test can sometimes provide information for the whole family without the at-risk generation being tested at all.

Practical sequencing, if insurance still matters to you

Even with the new law, a few steps are worth getting in the right order.

Check what cover you already hold, including inside superannuation, and whether it is adequate. Existing policies are unaffected by a later test result and the insurer does not need to be told, provided premiums continue. Varying a policy, however, triggers disclosure obligations — so check before you change anything.

Know that family history is still disclosable and usable. If you have an affected parent, that is the material fact for an insurer, test or no test.

If you are carrying a loading or exclusion from a pre-October 2026 disclosure, get advice about whether new cover would now be offered on better terms. The ban applies to new and varied policies from 8 October 2026, so this may genuinely be worth revisiting.

Get independent advice. A financial adviser or insurance broker with no stake in the outcome, and ideally one who has read section 33H. Community legal centres can also help where there is a dispute, and the Australian Financial Complaints Authority is free to use.

And do not let insurance be the reason you don’t talk to a genetic counsellor. The counselling appointment is free, it is confidential, and having it does not create a test result or any disclosable fact. People routinely spend years deciding whether to make an appointment at which they could have discussed whether to make a decision.