Minister's moral dilemma as sister pleads to make cancer risk known

Donor-conceived woman Katherine Vine has been endeavouring to alert her biological siblings to a family risk of bowel cancer.

She says she has a 35-year-old half-sister who is potentially unaware of the genetic danger, despite a 2024 law change that grants donor-conceived individuals greater access to knowledge about biological family.

In a bid to identify and notify her half-sister, Ms Vine wrote to the SA government which initially knocked back her request on privacy grounds but has since attempted to devise a compromise solution.

The case of a donor-conceived woman who desperately wants to warn her unknown half-sister of a family cancer risk has been described by South Australia's health minister as one of the trickiest ethical dilemmas he has faced during his time in the job.

Katherine Vine has more than 50 confirmed half-siblings who were conceived from the same donor, and her research into her family tree has led her to identify an elevated bowel cancer risk.

"It's serrated polyposis syndrome, and you just need preventative checks like colonoscopies, but much younger than you would normally," she told 891 ABC Adelaide.

For several years, she has been pushing for reforms that would make it easier for donor-conceived individuals to pass on important medical information to biological siblings whom they have never met.

She said she had become aware of a 35-year-old half-sister who may not know she was donor-conceived and is potentially unaware of the genetic danger, which could in turn have been passed on to any children she has.

In an effort to notify her half-siblings, Ms Vine wrote to the state government — which in 2024 introduced law changes to grant donor-conceived individuals greater access to knowledge about their biological parents, via an online register.

"I was told that the significance of the information and potential detriment to [my half-sister's] wellbeing overrides the potential benefits of the health information," Ms Vine said.

While Health Minister Blair Boyer has since had a change of mind, he said he made his initial decision after giving prolonged thought to the competing considerations around health risks and family privacy.

"The potential damage to the person and the family here by unknowingly alerting them to the fact that they may have been, or were, donor-conceived outweighs the import of the information regarding a potential health risk, and that it's not really government's place to be revealing that information," he said.

"That's a hard consideration to make because you can't put yourself completely in the shoes of the half-sibling about whether or not they would desperately like to know this, or whether they might know they're donor-conceived and have actively made a decision not to find out [more information]."

Mr Boyer said although Ms Vine's half-sister may not know she is donor-conceived, or does know but "has chosen not to be on the register", the thought that she might have children of her own "weighed on my mind".

"She could potentially develop cancer based on this genetic predisposition of which Katherine is aware, and maybe not be there for her kids, or possibly even that that could be passed on down to her kids unknowingly," he said.

Mr Boyer said that, after "struggling" with the issue, he had for the time being settled on what he described as an "alternative, third way".

"The biological mother of Katherine's half-sibling is obviously aware that Katherine's half-sibling is donor-conceived," he said.

"We landed upon the idea that … if we could contact her, we would not be revealing anything to her around the donor conception that she did not already know, and then have a conversation about potential health advice being available to Katherine's half-sibling without unwittingly … causing damage to a family where that perhaps hadn't ever been discussed."

Mr Boyer said that compromise in no way guaranteed a solution, because he could not be certain that Ms Vine's half-sibling's mother was still alive.

"I am very much hoping, given that Katherine's half-sibling is 35 years old, that she is and she will respond to us," he said.

Ms Vine said she was "incredibly grateful" for that tentative outcome, but stressed that she remained anxious to pass on the information about her polyps.

"I just think, 'God, I've had three, and this sister, she's a year younger than me, and might have kids' — I just don't want anything to fall on that family," she said.

"My plea is for any parents that have ever used a donor to conceive to please tell their children and go to the donor conception register that's open now, with counselling."