PGD and PGS

How do we test for known genetic conditions?

A gene is a sequence of DNA (genetic material) on a chromosome with a particular function. When the DNA sequence on a particular gene is altered, a genetic abnormality such as cystic fibrosis or thalassaemia may result. It is now possible to test for many hundreds of single gene disorders with Preimplantation Genetic Diagnosis (PGD).

TasIVF provides patients with access to the very latest technology in the field of PGD, Karyomapping. Karyomapping can test for a large number of single gene disorders including:

• Huntingtons’ disease
• Cystic fibrosis
• Thalassaemia
• Duchenne muscular dystrophy
• Fragile-X
• BRCA1/BRCA2 (hereditary breast/ovarian cancer)

There are some disorders where, although it is apparent from the family history that is cause is genetic, the exact gene is simply not known. In these cases, PGD using Karyomapping is not suitable. However, you will still be able to undergo PGD using the traditional PCR methodology. The PCR methodology requires the development of individual gene sequences that can be matched with the exact mutation that you are carrying.

Some people have a parent affected by a serious genetic condition, such as Huntington’s disease, that does not generally manifest until later in life. Many people do not want to have testing to determine if they have inherited that condition from their parent, however do not want to risk passing it on to their own children. In these cases, we can use exclusion testing to ensure the embryos have not inherited the ‘at risk’ gene.

Who should consider Preimplantation Genetic Screening?

Your TasIVF fertility specialist may recommend Preimplantation Genetic Screening (PGS), in combination with an IVF cycle, if:

• You have experienced repeated IVF implantation failure or recurrent miscarriage
• You have had a previous pregnancy affected by a chromosomal abnormality (such as Down syndrome), or
• You are of advanced maternal age (over the age of 38 years).

At TasIVF, Embryo Screening or PGT-A, is performed using Next Generation Sequencing technology which enables all 24 chromosomes in a developing embryo to be analysed prior to implantation. This allows selection of the embryo with the greatest likelihood of pregnancy success.

Testing for a translocation

In some people, part of one chromosome attaches to the end of another, or pieces of chromosomes may break off and be swapped around so although that person has a normal complement of chromosomes their embryos could inherit missing or extra pieces of chromosome. This is known as ‘unbalanced translocation’.

Embryos with unbalanced translocations usually do not implant, miscarry or rarely, result in the birth of a child with severe abnormalities. PGD can detect unbalanced translocations, as well as errors of all other chromosomes in a developing embryo.

Can PGD be used for gender selection?

Some genetic conditions affect only one gender, for example haemophilia and muscular dystrophy. Sometimes it is not possible to detect the exact genetic error that causes the disease and PGD is used to determine the gender of embryos and any errors of all other chromosomes. Then, only the embryos of the required gender and with the correct number of chromosomes will be transferred.

Gender selection is prohibited in Tasmania for non-medical, family balancing reasons.

How much does PGD or PGS cost?

At TasIVF the cost of PGD using Karyomapping is $1,640 for the preliminary evaluation plus $700 per embryo tested with a maximum fee of $2,460 for six or more embryos from one stimulated IVF cycle.

The cost for PGD or PGD using PCR or CGH technology is $700 per embryo with a maximum fee of $3,995 per stimulated IVF cycle.

The cost of PGD or PGS is in addition to your IVF cycle cost.

The cost of PGD can vary depending on your individual circumstances. A new Medicare rebate is now available for eligible couples and individuals, for pre-implantation genetic testing (PGD) of embryos for specific genetic or chromosomal variations prior to implantation. To find out if you may be eligible to receive the rebate please see the Medicare criteria via our FAQ's here.

If you have any questions about the cost of pre-implantation genetic testing with TasIVF please discuss this with your IVF specialist or genetic counsellor.