We’ve all seen the ads for genetic ancestry testing - as a way for people to trace their genealogy beyond traditional family trees and historical detail. And thanks to shows like CSI, the public might think of DNA as an investigative tool for the Police; a silver bullet that can solve any high-profile case in just minutes. But DNA can be used for much more than law enforcement activities or tracing ancestry.

The Law Commission – Te Aka Matua o te Ture – is currently reviewing the use of DNA in Police investigations. While its review focuses on Police DNA analysis and databanks, it also raises some significant questions that relate more broadly to privacy and health issues.

Genetic profiling might reveal genetic disorders

The Law Commission’s review considers how DNA profiles generated for criminal investigatory purposes may also reveal a genetic disorder, including conditions the individual may not yet be aware of. For example, testing can determine if a person has the genetic markers for Huntington’s disease, which is fatal and currently has no cure.

As doctors will be aware, genetic testing can confirm a diagnosis when symptoms are present and there is a documented family history of a particular disorder. However, some people who have a parent with a disorder will choose to be tested before presenting with any symptoms. Others choose not to be tested at all - even if it is an available option.

Medical genetics specialists will generally only make a DNA test available alongside full genetic counselling and a psychological evaluation because of the risk of harm from receiving such sensitive information if the patient is not fully prepared for it. Revealing genetic disorders without this kind of support could result in significant psychological distress for the patient.

Genetic information may affect life and health insurance

Alongside the psychological impacts of testing positive for a genetic disorder, this information may also affect a patient’s possibility of obtaining life and health insurance. Some countries have enacted legislation to restrict or ban the use of genetic information by insurance companies, so that insurance providers can’t charge higher premiums or exclude insurance cover if an individual has a genetic risk marker for particular conditions or diseases.

Future genetic testing is likely to provide even more information

Commercial genetic tests are currently marketed for tracing ancestry, and there are questions about how accurate these tests might be. But with advances in genetic science, it’s likely that commercial tests in the future could reveal significantly more information about an individual.

The Law Commission considered whether there are circumstances when Police may have a duty to disclose information about a genetic disorder to an individual. The review raised as an example malignant hyperthermia, which can cause death and can now be diagnosed by a DNA test.

If this type of information came to Police attention from a DNA sample analysed as part of a criminal investigation, should Police be required to disclose that to the individual, who may not know they are at risk? Or, if an individual makes a Privacy Act request for their own genetic profile, what are the consequences if they inadvertently learn more about themselves than they were prepared for?

Conceivably, in the future your patients may receive information about a genetic disorder or risk factor which they have tested positive for, but for which they are unprepared. They may well have many questions that you will have to assist them with.

Updating the law

There are no easy answers to these issues, but it’s important to give some thought to what the future holds. The Law Commission recommends that the Criminal Investigations (Bodily Samples) Act should be replaced with a law that is more up-to-date with scientific advances.

Other legislation or regulation might also be necessary to control what commercial DNA testing companies can test for, or how patients should be told about genetic disorders for which they have tested positive. In the meantime, general practitioners will want to be aware of the work being done in these areas and be prepared to answer questions about what DNA results might mean for your patient’s health.

First published in New Zealand Doctor on 22 May 2019.

Image credit: New Zealand Law Commission logo.

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