Alison Gee talks PGD

What is Rare Disease Day and how will Genea be raising awareness of it on the 29 February?

Rare Disease Day is an annual, awareness-raising event held on 29th February 2012.

On this day hundreds of patient organisations from more than 40 countries are organising awareness-raising activities converging around the slogan “Rare but strong together”.

Genea works with many families whose lives are affected by a genetic disease. To help raise awareness of the day, our staff will be wearing ‘Casual for a Cause’ on the 29th of February and donate a gold coin to charities associated with the rare disease – Juvenile retinoschisis.

What is PGD testing?

PGD (Preimplantation Genetic Diagnosis) is an advanced screening technique that can determine if an embryo has an identified genetic condition.

PGD is most commonly used by couples who know there is a possibility that their children risk inheriting a genetic condition.

Testing can involve a count of the chromosomes and/or a molecular examination for a particular gene mutation.

What is the difference between a gene, a chromosome and DNA?

A human being is made up of millions of cells. Inside each of these cells is a small chemical called DNA.  DNA is the building block of genes and these genes give individuals their specific characteristics such as blue eyes or brown hair.

The string of DNA is extremely long but coiled up like a really tight spring. This coiled DNA is called a chromosome. Each human being has 24 pairs of chromosomes.

How long has Genea offered PGD testing?

Genea first launched chromosome testing of embryos in 1995 and expanded this to single gene testing in 1998. Our techniques have developed and expanded since we first conducted genetic testing; many clinics have followed our lead and modelled their tests on ours.

Who can benefit from PGD?

PGD may be recommended for people who:

• Are affected by or carry a known genetic disease
• Are at an increased risk of chromosomal abnormality; have had recurrent miscarriages, failed IVF treatment or are of advanced maternal age

What do CGH and PCR stand for? What is the difference between the two?

CGH stands for Comparative Genome Hybridization.  CGH is a test that allows us to determine if the correct number of chromosomes is present in an embryo.

PCR stands for Polymerase Chain Reaction.  PCR is a test that allows us to look at the specific DNA sequences that make up our genes.

How many diseases can Genea test for?

More than 2,000 single gene disorders have been identified and Genea is capable of building a test for any one of them.

To date, we’ve been asked to test for approximately 170 disorders. This will increase as patients request PGD on some of the more rare disorders.

What is the most commonly screened disease?

Cystic fibrosis. It is also the most common life threatening, genetic condition affecting Australian children with an incidence of one in 2,500.

Cystic fibrosis affects about one per cent of the worldwide population with the highest frequency in communities of European origin.

How do our scientists conduct PGD?

Everyone’s DNA is different and so a unique test needs to be developed for each couple requesting PGD. It takes 10-12 weeks to develop the test, known as the genetic work up.

A genetic work up requires a blood sample from each partner and may require additional samples from other family members. It is a time consuming and complex job that ultimately enables our scientists to identify all the affected and non-affected DNA patterns. Embryos created using the IVF process can then be screened to determine if they have inherited a normal or faulty version of the gene.

How many DNA samples are required to perform the genetic work up?

It varies between families and disorders, but we always require DNA from the couple. It may also help to collect DNA from other family members.

At what stage of embryo development are PGD tests conducted?

Embryos develop in the laboratory for five days until they reach what is called the blastocyst stage, before a biopsy is performed to remove a small number of cells for PGD screening.

How accurate are the tests?

Our tests are between 90 to 99 per cent accurate, depending on the specific disorder and the technology being used.

What is a translocation?

Translocations occur when part of a chromosome breaks off and is attached to another chromosome. In a balanced translocation, no information is lost or gained and the individual is not affected. An unbalanced translocation leads to the loss or gain of genetic material and can result in miscarriage or abnormalities.

What is aneuploidy?

Aneuploidy is the term for an abnormal number of chromosomes, due either to an extra or missing chromosome. It is the most common cause of miscarriage and may contribute to abnormalities observed at birth such as Down syndrome.

How many scientists are on the PGD team?

We have six PGD scientists on the team.

Which Genea clinics offer PGD?

Genea offers PGD at the following clinics:

• City
• South West
• Northwest
• Hollywood, Perth
• Newcastle
• Canberra

What is the PGD Assistance program and who is eligible?

The PGD Assistance Program has been developed to provide Preimplantation Genetic Diagnosis to families that struggle to afford the out of pocket cost of IVF cycles and PGD screening.

To be eligible for assistance, applicants must be able to demonstrate the need for financial support. Couples also need to provide details of their current health status and medical history.

As age plays a significant factor in the success of treatment, applicants must be no older than 37 at the time of their application.

To date, Genea has treated 15 patients on the PGD Assistance Program, with 7 ongoing pregnancies and our first birth in January 2012.

For more information please click here.

Find out more about natural fertility at Genea Holistic or call us on 1300 367 198