Mackenzie’s Mission

Mackenzie

The diagnosis of a severe genetic condition in a child can be devastating for a family.

This was the experience of Rachael and Jonathan Casella just weeks after the birth of their daughter, Mackenzie, when she was diagnosed with spinal muscular atrophy (SMA).

SMA is a severe inherited neuromuscular condition without a cure.

Jonathan and Rachael had never heard of SMA. Neither were they aware that if they’d had a genetic test before falling pregnant they would have learned they were carriers of SMA.

As ‘carriers’ of this genetic condition, Jonathan and Rachael do not have the condition themselves, but have an increased chance of having a child with SMA.

In October 2017, Mackenzie Casella passed away. She was 7 months and 11 days old. Believing no couple should face this tragedy, the Casellas launched a campaign to raise awareness of genetic carrier screening, calling for this screening to be routine and free for all prospective parents in Australia.

Jonathan, Rachael and Mackenzie Casella

In the May 2018 Budget the Australian Government allocated $20 million to a research study of reproductive genetic carrier screening for about 500 severe and life-limiting genetic conditions including SMA, fragile X syndrome and cystic fibrosis.

The study was named Mackenzie’s Mission.

Read Mackenzie, Rachael and Jonathan’s story here

Mackenzie’s Mission

The Australian Reproductive Carrier Screening Project.

Mackenzie’s Mission is a research project in which couples will be offered screening to identify those with an increased chance of having children with debilitating and often fatal genetic conditions. Couples will also be tested for conditions where early treatment can improve a child’s health.

During the carrier screening project, 10,000 Australian couples will be screened before they conceive or in early pregnancy.

These couples will be offered information and support to help them make informed choices about whether or not to have the test, which involves a simple mouth swab or blood test.

If they are found to have an increased chance of having a child with one of the genetic conditions they will be supported and informed about their reproductive options, enabling them to make choices according to their own values.

The project will test for about 500 recessive and X-linked genetic conditions: conditions passed on to children from parents who are ‘carriers’ of the condition but who do not have it themselves.

Researchers will evaluate the outcomes of screening, the psychosocial impacts reported by couples, the ethical issues raised by reproductive carrier screening, and the health economic impacts of this test.

They will also investigate how reproductive carrier screening should be provided as a national program, with the long-term aim of making screening free for every Australian couple who wants it.

The project will start in Victoria, Western Australia and New South Wales. It is expected that couples in these states will be able to participate in the study from late 2019. The study will then open in all other states and territories through participating health professionals in late 2020. It is scheduled to finish at the end of 2021.

Mackenzie’s Mission is the first project to be funded from the $500 million Australian Genomics Health Futures Mission – part of the Australian Government’s Medical Research Future Fund.

Lead Investigators

Prof Edwin Kirk
Sydney Children’s Hospital & NSW Health Pathology

Prof Martin Delatycki
Victorian Clinical Genetics Services & Murdoch Children’s Research Institute

Prof Nigel Laing AO
Harry Perkins Institute of Medical Research and The University of Western Australia

Program Coordinator

Jade Caruana
Australian Genomics

Investigators

A/Prof Nicholas Pachter
Genetic Services of Western Australia

A/Prof Kristine Barlow-Stewart
The University of Sydney

Prof Paul Scuffham
Griffith University

Dr Michelle Farrar
University of NSW

Dr Damien Bruno
Victorian Clinical Genetics Services

Dr Mark Pertile
Victorian Clinical Genetics Services

Dr Sebastian Lunke
Victorian Clinical Genetics Services

Investigators

Dr John Beilby
PathWest Laboratories

Dr Mark Davis
PathWest Laboratories

A/Prof Ainsley Newson
The University of Sydney

Prof David Amor
Victorian Clinical Genetics Services

Prof Stephen Robson
Royal Australasian & New Zealand College of Obstetricians and Gynaecologists

Prof Jon Emery
The University of Melbourne & Royal Australian College of General Practitioners

Prof Leslie Burnett
Garvan Institute of Medical Research

Investigators

Prof Sue Walker
Mercy Hospital for Women & The University of Melbourne

Sheila Handbury
The University of Melbourne

Dr Michael Buckley
NSW Health

A/Prof Tony Roscioli
Sydney Children’s Hospital, Randwick & Neuroscience Research Australia

Prof Jeffrey Braithwaite
Australian Institute of Health Innovation
Macquarie University

Prof Jane Halliday
Murdoch Children’s Research Institute

A/Prof John Massie
The Royal Children’s Hospital & Murdoch Children’s Research Institute

Investigators

Dr Alison Archibald
Victorian Clinical Genetics Services

Ms Samantha Edwards
Harry Perkins Institute of Medical Research

Ms Kirsten Boggs
Sydney Children’s Hospital & The Children’s Hospital at Westmead

Dr Corrina Cliffe
NSW Health Pathology

Dr Stefanie Eggers
Murdoch Children’s Research Institute

Dr Samantha Sundercombe
Liverpool Hospital

Dr Justine Marum
Victorian Clinical Genetics Services

Investigators

Mr Royston Ong
Harry Perkins Institute of Medical Research

Dr Tristan Hardy
SA Pathology and Women’s and Children’s Hospital

Dr Cliff Meldrum
NSW Health Pathology

Prof Julie McGaughran
Genetic Health Queensland

Dr Jan Liebelt
South Australian Clinical Genetics Service

Ms Lindsay Tuer
Victorian Clinical Genetics Services

Dr Chiyan Lau
Pathology Queensland

Investigators

Dr Janice Fletcher
SA Pathology

Dr Alison Colley
Liverpool Hospital

Ms Kate Dunlop
Centre for Genetics Education NSW

A/Prof Clara Gaff
Melbourne Genomics Health Alliance

Dr Lucy Gilkes
The University of Western Australia

Dr Simon Morgan
GP Synergy

A/Prof Meredith Wilson
The Children’s Hospital at Westmead

Ms Rachael Casella and Mr Jonathan Casella
Parents of Mackenzie

For all enquiries relating to Mackenzie’s Mission, please contact mackenziesmission@australiangenomics.org.au

FAQs – Mackenzie’s Mission

Every person has two copies of most genes – one from each parent.

A person is a ‘carrier’ when they have one copy of a faulty gene (a gene mutation) associated with a genetic condition, but their other copy of the gene is functioning normally. They won’t have the genetic condition themselves, but will be a ‘carrier’ of the condition.

A carrier can pass on this faulty gene or genes to their children. When a faulty gene associated with a genetic condition is passed on to a child by each parent – this means the child has two faulty genes and no healthy copy – the child will have the genetic condition.

It is estimated that all people are carriers of several recessive genetic conditions, without ever realising it. When two people who carry a fault in a gene for the same condition have children, for each pregnancy, there is a 1 in 4 (25%) chance that their child will inherit faulty copies of the gene from both parents, and have the genetic condition.

Image shared with permission of the Genetic Support Foundation.

Women have two X chromosomes and men have one X and one Y. If there is a faulty gene on the X chromosome it can cause a genetic condition. Usually boys and men are more severely affected by X-linked conditions than girls and women – women may be healthy carriers who do not show any signs of the condition.

Image shared with permission of the Genetic Support Foundation

Carrier screening is a form of genetic testing used to see if a person is a carrier of recessive or X-linked genetic conditions that could be passed on to their children.

When couples who are planning a family or are in the early stages of pregnancy have carrier screening, it is known as reproductive carrier screening. This means the test looks at the genetic information of both the mother and father together to see if, as a couple, they have an increased chance of having a child with a genetic condition.

Recessive and X-linked genetic conditions are a major cause of death and chronic illness in children. It is estimated that more than one million people in Australia are affected directly or indirectly by a genetic condition. Carrier screening for those planning a family, or in early pregnancy, enables couples to make informed choices according to their own personal wishes and values.

The Royal Australian and New Zealand College of Obstetricians and Gynaecologists have recently published the following recommendation to provide guidance on who should be offered reproductive carrier screening:

Information on carrier screening for the more common genetic conditions that affect children (e.g. cystic fibrosis, spinal muscular atrophy, fragile X syndrome) should be offered to all women planning a pregnancy or in the first trimester of pregnancy. Women wanting more information about carrier screening should be given the opportunity to have a more detailed discussion about carrier screening with an informed clinician. The benefits and limitations of testing, and any associated costs should be discussed.

Yes. Many countries have carrier screening in place for recessive conditions. In Australia, carrier screening for thalassaemia, a genetic blood disorder, is government funded and screening for other conditions including cystic fibrosis, spinal muscular atrophy and fragile X syndrome is available on a user-pays basis. Many countries have carrier screening programs for variable numbers of conditions with some being government funded and some being user-pays.

The project will screen for autosomal recessive and X-linked genetic conditions affecting children where those conditions are severe and life-limiting, and for those where early treatment can improve a child’s health.

It will include spinal muscular atrophy (SMA), fragile X syndrome (FXS), cystic fibrosis (CF) and around 500 other genes associated with severe, life-limiting conditions.

About 500 genes are being selected because this number is technically achievable and will make it possible to detect the great majority of couples who have an increased chance of having children with the recessive and X-linked conditions that affect Australian children.

No, this is a research study and participation is optional. Couples will be provided with information and support to help them make an informed choice about whether or not to participate.

Before reproductive carrier screening can be made widely available, a large pilot study needs to be done to answer some important questions like: How do couples feel about having carrier screening? What choices do couples make before and after having screening? What information do we need to provide health professionals to deliver screening? What resources does our health system need to ensure screening can be accessed by those who wish to have it? What infrastructure is needed for screening to be delivered at scale in the Australian population?

Ten thousand couples will be screened as part of the study. We aim to enrol a broad sample of couples that reflects the diversity of the Australian population. This is important to ensure the outcomes of our research are applicable to the population as a whole.

If a woman is pregnant at the time the couple is found to have a 1 in 4 chance of having a child with one of the conditions, there is the option of having testing of the pregnancy by chorionic villus sampling or amniocentesis (prenatal diagnosis). If the pregnancy is affected, termination of the pregnancy may be considered.

If not pregnant when identified to have a 1 in 4 chance of having a child with a genetic condition, then in addition to the option of prenatal diagnosis, couples could choose to have testing of embryos produced by IVF (preimplantation genetic diagnosis, PGD), use donor egg, sperm or embryo, adopt children or choose not to have children. One cycle of PGD will be available free of charge to all eligible couples identified through Mackenzie’s Mission.

For some conditions, early diagnosis can lead to more effective treatments. In addition to the options above, couples who are found to have an increased chance of having a child affected by such a condition may choose to test the child at birth.

Couples can enrol in the study only through health professionals involved in the study. General practitioners, obstetricians, midwives, geneticists and genetic counsellors at specific sites around Australia will recruit couples for the study.

Couples planning a family, or who are in early pregnancy, will be asked by their participating health professional whether they wish to be involved in the study. The health professional will then provide the couple with further information about reproductive carrier screening and the risks, benefits and possible outcomes of their involvement in the study, and details on how to enrol. A telephone helpline will be available for couples considering enrolling in the study to talk to a genetic counsellor, should they have further questions.

The project will start in Victoria, Western Australia and New South Wales. It is expected that couples in these states will be able to participate in the study from late 2019. The study will then open in all other states and territories through participating health professionals in late 2020. It is scheduled to finish at the end of 2021.

For more information about autosomal recessive and X-linked inheritance see:

Fact Sheet on Autosomal Recessive inheritance

Fact Sheet on X-linked Recessive inheritance

Mackenzie’s Mission is the first project to be funded from the $500 million Australian Genomics Health Futures Mission – part of the Australian Government’s Medical Research Future Fund.