Parents-to-be, would you want to know if you’re a carrier of a genetic condition?
By: Dr. Alison Archibald
Group Leader, Reproductive Genetics at VCGS
Carrier screening is relevant to everyone planning a pregnancy. Senior genetic counsellor, Dr. Alison Archibald talks about the importance of carrier screening in a couple’s reproductive journey.
“Approximately one to two percent of people who have genetic carrier screening learn that they have an increased chance of having children with a serious inherited condition.” - Dr. Alison Archibald, Group Leader, Reproductive Genetics at VCGS
Our research has shown 1 in 20 people in Australia are carriers of one of the three most common genetic inherited conditions in our population: cystic fibrosis (CF), fragile X syndrome (FXS), spinal muscular atrophy (SMA). Approximately 1 in 1,000 couples may have an affected pregnancy.
We have a long history in genetic carrier screening, being the first provider of general population carrier screening for CF in 2006 and developing the first three-condition carrier screen - adding FXS and SMA in 2012.
In 2018, we became partners in the Mackenzie’s Mission research study. This study looked at how best to implement carrier screening services within the population and offered testing to over 10,000 Australian couples.
In March last year, the Federal Government announced a new plan to make genetic carrier screening for CF, SMA and FXS accessible under Medicare, with the funding forming part of the 2022/23 Federal Budget.
ABOUT MACKENZIE’S MISSION
Mackenzie was a perfect little baby – the picture of health, but at 10 weeks old, she was diagnosed with a condition called spinal muscular atrophy (SMA) – a severe inherited neuromuscular condition without a cure.
Mackenzie’s parents Rachael and Jonathan Casella were devastated. The couple had no family history of genetic conditions and undertook all the recommended preparations to have a healthy child. They had never heard of SMA and weren’t aware they were both genetic carriers for the condition. As ‘carriers’, the couple do not have the condition themselves, but have an increased chance of having children with SMA.
In October 2017, Mackenzie Casella passed away at just seven months and 11 days old. Believing no couple should face this tragedy, the Casellas launched a campaign calling for reproductive genetic carrier screening to be routine and free for all prospective parents in Australia.
What is reproductive genetic carrier screening?
Reproductive genetic carrier screening is genetic testing that can tell people if they have an increased chance of having children with a serious genetic condition. Approximately one to two percent of people who undergo genetic carrier screening learn that they have an increased chance of having children with a serious inherited condition.
What conditions can be screened?
The current options available can be grouped into two categories:
Small panel screening which focuses on common, severe conditions where evidence supports screening. This is typically offered as a three-condition screen, screening for the most common inherited conditions in our population (CF, FXS and SMA).
Large panel screening includes a much wider range of conditions which are present in childhood and are often severe. This includes common conditions as well as many rare conditions.
VCGS was the first in Australia to provide genetic carrier screening for the three common inherited conditions (CF, FXS and SMA), through one test - later called prepair 3.
A few years later, we expanded our screening to cover a wider range of genetic conditions, covering over 500 genes. We called this test prepair 500. And this year, we've launched Australia’s first carrier screening service that covers more than 1000 genes: prepair 1000+.
Learn more about prepair screening options.
Who should have genetic carrier screening?
Reproductive genetic carrier screening is relevant to everybody - either before or in early pregnancy, regardless of family history, ethnic background or ancestry. Our research shows the number one misconception about carrier screening is that individuals believe they must have a family history in order to consider screening. What we know, however, is that most children with these conditions are born into families where there is no prior history.
Who can I talk to about carrier screening?
Families come in all shapes and sizes, and carrier screening is relevant to everyone. Deciding whether to have carrier screening as well as which option to take, is a personal decision.
Our genetic counsellors are available to answer all your questions about carrier screening. Genetic counsellors can help you consider the pros and cons and decide which option is the best for you and your personal situation.