IVF parents have helped scientists at fertility clinic Genea to achieve a world first by developing stem cells known to carry a rare incurable eye disease.
Studies on the stem cells may potentially unlock the mystery of the condition and lead to new treatments.
The stem cells known to carry the genetic disorder juvenile retinoschisis (JR) were grown in the lab by Genea scientists using embryos that were donated to research by parents Sheree and Peter Staggs.
When the couple, from Gilgandra, considered starting a family they knew there was a 50 per cent chance that a boy would be affected by JR and a 50 per cent chance that a girl would be a carrier of the condition that has affected Sheree’s father and three of his brothers – leaving them with very limited vision.
They decided to use preimplantation genetic diagnosis (PGD), a technique to screen embryos for identified genetic diseases during an IVF cycle.
The couple’s two sons, Tom, two-and-a-half and Joe, nine-months, were born following five cycles of IVF with Genea fertility specialist Dr Alison Gee.
“Sheree and Peter’s experience is a real testament to the value of being able to utilise PGD as a treatment option for families with genetic diseases – rather than the alternative of conceiving naturally and having to consider terminating a pregnancy if testing later in the pregnancy reveals the baby has inherited a genetic disease,” Dr Gee said.
“Genea is a world leader in PGD and we can offer screening for almost any genetic disease – we have provided testing for around 170 genetic diseases to date.”
Delighted to have two healthy boys, the Staggs decided that three embryos that were known to be affected with JR should be donated to research.
Mrs Staggs, 33 said: “I was happy to donate the embryos. We were not going to use them and there was the potential for there to be benefit for other people, be that in Australia or anywhere in the world.”
The family are pleased to have contributed to the break-through that came after Genea research scientists discovered how to create embryonic stem cells lines carrying juvenile retinoschisis.
Tomas Stojanov, Genea CEO, said: “Stem cell research is very exciting. It provides a platform to discover how diseases work. The availability of disease-affected stem cells is the first step towards development of a laboratory disease model, which will help researchers to better understand the disease mechanism and ultimately to assist in the development of effective treatments.
“We are very proud to be at the forefront of this type of research.”
Embryo research is strictly regulated and can only be carried out under licence. Genea currently holds nine out of ten embryo research licences issued by the Australian Federal government and is a world leader in the field.
The stem cell bank at Genea includes 20 different diseases including Huntingdon’s disease, FSHD, myotonic dystrophy and Charcot-Marie-Tooth disease and research projects include collaborations with international disease experts.
Previously, two stem cells lines for another retinal disease – called vitelliform macular dystrophy – grown at Genea have been used by Dr Michael O’Connor at the University of Western Sydney, for his work developing disease models.
It is hoped a similar collaboration will take place to learn more about the progression and potential treatment of JR from the stem cell line produced from the Staggs’ embryos.
About pre-implantation genetic diagnosis (PGD) at Genea
Human beings are made up of billions of cells. Inside the centre of these cells are small chemicals called DNA. Our DNA consists of thousands of genes. It is our genes that define specific characteristics, including hair and eye colour.
Genes - or more specifically abnormalities in genes - are also responsible for many inherited diseases. We are now able to identify more than 2,000 single gene disorders that cause specific diseases and have developed tests to screen for 170 conditions. Examples of diseases resulting from single gene disorders include cystic fibrosis, fragile X syndrome, muscular dystrophy and Huntington’s disease.
At Genea, we are able to offer families with a history of single gene disorders preimplantation genetic diagnosis (PGD). This involves an IVF cycle – where the woman is given hormones to stimulate the ovaries to develop more eggs than usual that are then retrieved. The eggs are fertilised with the partner’s sperm in the lab to form an embryo.
Embryos from PGD patients are developed for five days. At this point, known as the blastocyst stage, they contain about 100 cells. A tiny number of cells can be removed and analysed to determine if they carry the genetic disorder. The couple are able to find out which of the embryos has a healthy version of the gene, which are carriers of the faulty gene and which will be affected by the disorder.
The PGD process allows couples to select an embryo for transfer that is disease free.
Patients are given the option of allowing the affected embryos to be donated to research. These embryos that are known to be affected or carriers of specific genetic diseases have the potential to offer new insights into the mechanics and progression of currently incurable diseases.
The ability to produce stem cells – known as stem cells lines – that are known to be affected with a particular genetic disease provides a unique opportunity to study the early development of the condition - this work may ultimately lead to better treatment options.
About stem cell research at Genea
All human life begins with the fertilisation of one egg by one sperm. During IVF conception, this takes place in a dish in a laboratory. As the fertilised egg develops, it divides to form new cells that eventually make up the embryo and fetus.
Early-stage embryos, usually less than seven days old from fertilisation, contain cells that in a laboratory are able to form embryonic stem cells.
Each of these cells has the ability to develop into any kind of human cell – for example some will become liver cells, others neurons, others skin cells. It is still largely a mystery how, in nature, these cells specialise into all their various functions within the developing embryo.
Stem cell research at Genea focuses on the creation of new embryonic stem cell lines carrying inheritable diseases and developing methods to turn stem cells into the adult cell types affected by disease.
This is technically very challenging and success relies on providing the right signal, in the right place, at the right time. The Genea research lab is one of only a handful in the world using robotics to screen hundreds and thousands of combinations of signals in microscopic cultures.
Once a specific stem cell line and a protocol to turn it into the disease-affected cell type has been developed by Genea scientists, it can be used by researchers and pharmaceutical and biotech companies to increase the understanding of how diseases progress and to test potential treatments by analysing how the cells behave when exposed to certain drugs.
About juvenile retinoschisis
Also known as, X-linked retinoschisis, it is an inherited eye disorder that causes the inner layer of the retina to split. It usually occurs in both eyes at once and occurs almost exclusively in males.
It is usually diagnosed in childhood and causes progressive loss of vision which varies, with some people retaining useful vision into adulthood but others experiencing a rapid decline in childhood.
It is an X-linked inherited disease carried by mothers and passed on to sons. A carrier mother has a 50 per cent chance of having a son who is affected and a 50 per cent chance of a daughter who will be a carrier.
About Dr Alison Gee
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