Genomics: Would you test your child?

Most parents will be familiar with the hearing screening offered to their newborn in their first few days of life, and the heel prick test (officially called bloodspot screening) to identify if they are affected by one of 24 serious and treatable diseases.

But what if this test helped us learn even more about our child’s health? Recently, Australian researchers from Melbourne’s Murdoch Children’s Research Institute set out to discover if parents were offered additional genetic information about their newborn, would they accept it? 

The study, called the Baby Beyond Hearing project, was an Australian first.

Previously, researchers have asked parents if they would like this information, but the offer has always been hypothetical. This time the offer was both real life and in real time.

Put simply, genomic testing means testing the whole of a person’s genetic makeup.

In Baby Beyond Hearing, the researchers studied parents of children who had already been diagnosed with deafness. When parents consented to the study they were offered three choices of genomic testing.

With Option A, their child’s genome would be analysed only for genes relevant to deafness. If they chose Option B, researchers would also test for other genes associated with childhood-onset conditions, but only conditions for which there is a known treatment or intervention. 

Option C took parents’ decision-making even further: those choosing this route had their child’s genomes analysed for genes relevant to deafness, and additional genes associated with childhood-onset conditions, however, this time researchers added in detection of genes which may not have a clear treatment option.  

It was a new way of using genomic testing.

“Primarily at the moment we are using genomic testing in children who are already sick, to see if we can identify the cause of their health problem. In this particular research project we are looking at the potential to use the technology very early on in life before a child becomes unwell,” says Professor David Amor, a clinical geneticist and paediatrician with MCRI and co-author of the study.

Researchers were particularly interested in whether parents would go beyond the option to only look for serious but treatable diseases.

“We were really interested in whether parents wanted more information, given that currently the options usually look only at serious, treatable diseases,” says clinical geneticist and paediatrician with MCRI and co-author of the study, Dr Lilian Downie.

Both agree the question itself poses challenges.

“Of course, [knowing this information] has obvious potential benefits, in that you may be able to prevent certain illnesses from occurring. But it has certain downsides as well: it’s pretty confronting information to potentially give a parent. They may not want this information,” Professor Amor says. 

What researchers found

Of the 106 families who agreed to have genomic testing in the study, 72 (68 per cent) consented to receive genomic analysis beyond the deafness genes.

Of those, 29 (27.4 per cent of all respondents) opted for Option B while 43 (40.6 per cent of all respondents) opted for Option C. A sizeable 32 per cent of families, however, opted only to analyse genes directed related to their child’s hearing impairment (Option A).

The results reiterated something researchers believe is of key importance if this type of testing is offered more broadly.

“The main finding was that one size doesn’t fit all. Two thirds of parents wanted additional information, but one third weren’t interested in it at that point in time. What stood out for us was that it’s important to take into account that people want different things,” says Dr Downie

She says the results may have been different if the testing was done at a different time in a child’s life.

“Having a new baby is a significant time, so parents might change their mind if it was offered later, and they were offered more information or additional genetic counselling,” Dr Downie says.

Researchers also discovered that, regardless of which option parents chose, participants mostly demonstrated low levels of anxiety and feelings of conflict or regret around the decision to have genomic screening – the first quantitative data on psychosocial impacts that has been published to date.

By analysing both the ‘yes’ and the ‘no’ groups, researchers could see that three issues played a role in parents’ decision making.

“Family size had a little bit of an impact – if it was their second child they were more interested in wanting the additional information,” says Dr Downie.

Families identifying as Australian were also more likely to want to have the testing done than those from other cultures. Thirdly, parents with very young newborns (under three months) were less inclined to want the extra information.

“It will be interesting to explore all these factors in interviews…It may be that people need a period of time with their babes before considering that type of testing,” Dr Downie says.

Professor Amor agrees that if the testing was applied to the general population, best practice may require it to be conducted separately to the existing newborn screening tests parents are already used to.

“We have greater than 99 per cent uptake within the community on the current newborn screenings. For the vast majority of babies that are born, their parents are very happy – in fact, enthused – for screening to occur,” Professor Amor says.

Considering the ethics of genomic testing

As clinical geneticists and paediatricians, both researchers were well versed in the ethical issues that come with the rapidly advancing technologies used in genomic testing.

“We are very interested in how that technology is applied in a clinical setting to generate the best health benefits for the community while at the same time, minimising potential negative outcomes,” Professor Amor.

While none of the families in this study were dealt devastating news as a result of the testing, that would change if the tests were done on a population level.

“It would really require genetic counsellors or people who were well trained about the technology we are using to have an information session with parents, which takes quite a long time,” says Dr Downie.

While rolling out this type of testing at scale isn’t an option today, that may change quickly.

“At the moment, we mostly deal with this kind of technology with patients who come through the door having a suspected genetic diagnosis. We are not applying this type of testing to healthy people, whether adults or children. But there’s a general view that we will see more of this in the next decade,” Professor Amor says.