Children free of HSP
If you are intending to have children and know or suspect that you or your partner might have HSP, now there is the opportunity to explore ways to prevent children inheriting the disease.
Briefly here is how it goes:
- The 1st step is to discuss the whole process with a genetic counsellor* so that you are well-informed and well-placed to make good choices.
- Gene testing to see if you have one of the types of HSP that can be tested for (currently 3 types in Australia covering about half of all HSP occurrence).
- If a positive test is found, then options are available to help ensure a child does not inherit the disease.
In vitro fertilisation (IVF) is a process in which egg cells and sperm are collected from prospective parents (or donors in some cases), and then fertilisation takes place in the laboratory (in vitro). IVF generally is a treatment for infertility when other methods of assisted reproductive technology have failed.
In a standard IVF cycle, the woman’s ovaries are stimulated with hormones so that more eggs come to maturity than in a normal menstrual cycle. These eggs are collected and fertilised with the male partner’s sperm in the laboratory. Eggs that successfully fertilise (embryos) are supported for around five days in special incubators that mimic the conditions in the uterus. Not all embryos survive to Day 5. Of those that do, one is transferred in the uterus and the others are frozen for possible later use.
Donor egg or sperm
IVF can also be used with egg donation or sperm donation so the HSPer involved doesn’t risk passing HSP along to their children. This may be of interest to couples where the exact HSP gene fault cannot be identified by genetic testing. If the fertilisation is successful, the embryo can be transferred into the uterus, within which it may implant. Surrogacy, where the woman providing the egg isn’t the same one who will carry the pregnancy to term is also a possibility.
Where a genetic disorder such as HSP may be a factor, IVF can be combined with a technique called Preimplantation Genetic Diagnosis (PGD). This allows couples to rule out or detect the presence of a genetic disorder and ensure the HSP is not passed along. A similar but more general test has been developed called Preimplantation Genetic Haplotyping (PGH).
PGD involves carefully removing small number of cells from an embryo for analysis and detection of the known HSP mutation. Most commonly, PGD is used where a couple is aware of the possibility that their offspring will inherit a genetic disease. Even though they may not have a problem with fertility, they choose to undergo a stimulated IVF cycle with the aim of producing a number of embryos. Only embryos that do not carry the faulty HSP gene are transferred, ensuring the HSP is not inherited by the child.
IVF requires serious consideration
The IVF process can take time and money and requires serious consideration of the issues involved… detecting the HSP mutation; medical issues about having a baby for some HSPers; program availability, and cost.
Gene Testing / Genetic Counselling
It is a good idea to see a genetic counsellor* before genetic testing so that you understand the whole process, the issues, choices, commitments and decisions involved. Gene testing for an HSP mutation is the next step. Testing currently available in Australia covers around half of all HSP incidence, but there are high expectations of being able to detect upwards of 80% of all mutations within a couple of years.
Unfortunately, a negative or uninformative gene test result rules out PGD as an option. A positive test verifies the particular type of HSP carried by a prospective parent, or in some rare cases, by both parents.
Options the genetic counsellor will discuss include IVF, a third party donor, or further gene testing.
What about availability and cost?
From ABC Network (ABC Health and Well Being) http://www.abc.net.au/health/default.htm:
Availability and cost of genetic tests – useful things to know
- The particular tests offered may vary depending on where in Australia you live and your doctor’s level of knowledge.
- The cost of genetic testing to you may also vary widely depending on whether the test is covered by Medicare, whether you are requesting the test as a private patient of a doctor, or if at a public clinic, the budget of that clinic. Very few gene tests are covered by Medicare.
- Most tests offered through public clinics are wholly or partly subsidised, however, there may be long waiting periods (up to 12 months) for an appointment.
- The best way to find out about options regarding the availability and cost of a particular test is to contact a clinical genetics service.
60 Genetic Fact sheets are available from the Centre for Genetics Education website: http://www.genetics.edu.au/factsheet
Where is PGD or PGH currently available for HSP?
IVF facilities in Australia include:
- IVF Australia (http://www.ivf.com.au) locations in Victoria, NSW and Qld
- Genea (http://www.genea.com.au) locations in NSW
- Westmead Fertility Centre (http://www.westmeadivf.com.au) located in western Sydney
- City Fertility Centre (http://www.cityfertility.com.au) Qld, South Australia and Victoria
- repromed (http://www.repromed.com.au) South Aust., Northern Territory, Victoria
- Flinders Reproductive Medicine (http://www.flindersivf.com.au) South Australia
- Perth IVF (http://perthivf.com/) Western Australia
- TASIVF (http://www.tasivf.com.au/) Tasmania
They show cost information on their websites and include Medicare coverage information and payment plans offered. Some of the costs of IVF are covered by Medicare and are available to all Medicare cardholders. Out-of-pocket costs vary widely between IVF providers, so it can pay to compare.
* A clinical geneticist is a doctor with specialist genetics training. A genetic counsellor has genetic and counselling training and works with the clinical geneticist and the IVF team. Your GP, neurologist or nearest major hospital can help you with contact information for genetics services.