![Rachael and Jonathan Casella, with baby Mackenzie.](http://web.archive.org./web/20180403165635im_/http://www.essentialbaby.com.au/content/dam/images/h/0/w/i/a/p/image.related.articleLeadwide.620x349.p4z1bv.png/1519610723928.jpg)
When Rachael Casella was pregnant with her daughter Mackenzie, she chose to undertake myriad tests to optimise the chances of a healthy baby and pregnancy. But at no stage was she offered a straightforward saliva or blood test to see if she was carrying the Spinal Muscular Atrophy Type 1 gene.
The couple, who featured in a report on 7.30 on the ABC on Thursday night, lost Mackenzie to the disease when she was just seven months old. They had to endure the slow devastation of watching their daughter lose her muscle strength, her movement, her ability to feed, to swallow and finally to breathe before her first birthday.
Yet such tragedy could have been prevented if they had known about a simple genetic test they could have taken before or when Rachael was pregnant. The test for the SMA Type 1 gene has been available for some time through a pathology company that also screens for cystic fibrosis and Fragile X. Unfortunately it costs about $400 and parents do not receive a rebate through Medicare. And as Rachael and her husband, Jonathan, discovered, most GPs are not even aware of its existence.
![Jonathan and Rachel lost their daughter Mackenzie when she was seven months old.](http://web.archive.org./web/20180403165635im_/http://www.essentialbaby.com.au/content/dam/images/h/0/w/i/a/q/image.related.articleLeadwide.520x294.p4z1bv.png/1519610723928.jpg)
We have come a long way from the days when Down Syndrome was the main condition expectant mothers had testing for. Advances in technology mean the test for the SMA Type 1 gene that cut short Mackenzie’s life should be considered as part of routine preconception care.
A 40-year-old woman has about a one-in-100 chance of having a baby with Down Syndrome. Yet a recent Australian study showed that one in 20 women were carriers of at least one of the SMA, cystic fibrosis or Fragile X genes.
The scope for genetic testing is endless, but the test the Casellas should have been offered is one of the sensible options that can vastly reduce the risk of families going through the grief of losing a child.
Until the costs of such tests are reduced, funding the tests through Medicare should be a serious consideration.
The big problem is the lack of awareness among parents, GPs and obstetricians.
One stumbling block is that there are no Australian guidelines about genetic testing. The Australian College of Obstetricians states that couples planning pregnancy “may be offered” screening for conditions like SMA and cystic fibrosis. But the college falls short of actually recommending screening.
There are complex ethical issues at play too. What do parents do if they do take a test and find out they are carriers of a particular condition? The more information they have, the more choices there are to make, particularly when a couple decides to terminate an affected pregnancy.
But being able to undergo such tests will ultimately save the community the costs involved in caring for babies and children born with severe chronic conditions like cystic fibrosis and spinal muscular atrophy. And it will save parents the ordeal of losing a child.
Genetic carrier testing can be enormously successful. The Ashkenazi Jewish community is a good example. Individuals from this background have a one in 25 chance of carrying a recessive gene for Tay-Sachs disease, which is a progressive neurodegenerative disorder and means that affected children don’t live beyond five years of age.
Yet thanks to a comprehensive screening program in schools and the community to identify carriers, there have been no cases born to couples who have been screened in Australia since the 1980s.
As a geneticist at The Royal Hospital for Women, Randwick, I’ve counselled thousands of pregnant women, and the reality is that for every one of them, there is a 3 to 5 per cent chance of having a baby with a birth defect. Almost all of the parents I’ve seen over the years would prefer to have been informed rather than endure the grief the Casellas are experiencing.
Debra Kennedy is a geneticist at The Royal Hospital for Women, Randwick.