Guidelines for genetic testing of human embryos
4 October 2004
Views sought on guidelines for genetic testing of human embryos
The public is being asked for its views on proposed guidelines covering the testing of human embryos for serious inherited genetic conditions.
This week, public consultation begins on the proposed guidelines for preimplantation genetic diagnosis (PGD), which have been formulated by the National Ethics Committee on Assisted Human Reproduction (NECAHR). The submissions will assist in preparing a final set of guidelines, which will be submitted to the Minister of Health Annette King for approval early next year.
The discussion document and proposed guidelines are being distributed to fertility clinics, district health boards, professional organisations, consumer groups, government agencies, and individuals with an interest in the subject.
As well as calling for written submissions, NECAHR is holding a series of public meetings throughout the country to hear oral submissions. These will be held in the four main centres at the end of November 2004.
PGD is used in conjunction with in vitrofertilisation to test embryos for specific genetic conditions before they are transferred to a woman's uterus. The procedure is sought by both fertile and infertile couples at high risk of having children with a serious genetic condition.
While PGD is widely available overseas, it is not currently allowed in New Zealand. The only testing option available to couples at risk of passing on a genetic disorder to their child is prenatal diagnosis (PND), which is invasive and may result in a pregnancy being terminated. For some people, termination of a pregnancy raises unacceptable ethical concerns. PGD, however, involves making decisions about the future of an affected embryo, rather than an affected fetus.
In June last year, the Minister gave approval in principle for PGD to be offered in New Zealand, subject to NECAHR developing guidelines ensuring its safe and ethical use.
The consultation document sets out the scientific and ethical issues around PGD, together with details of the international situation.
The guidelines will prohibit the use of PGD for:
social reasons, including sex selection altering the genetic constitution of an embryo selecting embryos which have a genetic abnormality seen in a parent.
The Human Assisted Reproductive Technology Bill currently before Parliament proposes to ban sex selection for social reasons and the genetic modification of embryos for reproductive purposes.
Currently PGD can be used to test for three different types of abnormalities:
single gene defects which cause disorders, such as cystic fibrosis or Huntington's disease numerical chromosomal abnormalities (aneuploidy), which cause disorders such as Down syndrome or Turner's syndrome structural chromosomal abnormalities in which part of one chromosome becomes attached to another
Once the guidelines are finalised and approved, fertility clinics will be able to apply to NECAHR for approval to offer PGD locally.
NECAHR Chair, Professor Sylvia Rumball, said she welcomed submissions on any of the issues raised in the proposed guidelines.
"The guidelines will create boundaries around the use of PGD that will ensure the technology is not misused," she said. "The use of PGD for non-medical reasons will be prohibited. This technology is not about 'designing babies'. Its aim is to help carriers of serious genetic disorders have children without the risk of passing on an inherited condition."
The issue of public funding for PGD would be considered by the Minister once NECAHR had finished its consultation and provided the finalised guidelines to the Minister.
The discussion document and the proposed guidelines are available on the NECAHR website www.newhealth.govt.nz/necahr.htm
Written submissions close at 5pm on Friday 12 November 2004. They can be sent to:
The Secretariat National Ethics Committee on Assisted Human Reproduction PO Box 5013 WELLINGTON
Oral submissions will be heard in Dunedin on 22 November, Christchurch on 23 November, Wellington on 24 November, and Auckland on 26 November. For further information about the oral hearings contact firstname.lastname@example.org.
What is Preimplantation Genetic Diagnosis (PGD)?
PGD is a procedure used to test early human embryos for serious inherited genetic conditions. It can only be used in conjunction with in vitro fertilisation (IVF). IVF involves the collection of oocytes from a woman and sperm from a man, and the subsequent creation of an embryo outside the body for implantation into the women's uterus.
How is PGD performed?
PGD involves several steps:
the creation of an embryo via IVF the removal of one or two cells from the embryo the genetic testing of these cells for specific genetic conditions the subsequent transfer of unaffected embryos to a woman?s uterus.
Why have guidelines for PGD been created?
Currently, PGD is not available in New Zealand. However, last year the Minister of Health gave approval in principal to PGD and requested that the National Ethics Committee on Assisted Human Reproduction (NECAHR) develop guidelines on PGD for fertility clinics. The Guidelines for Preimplantation Genetic Diagnosis in New Zealand will help fertility clinics offer PGD to their clients in a safe and ethical manner.
What is PGD used for?
Currently, PGD can used for three different types of abnormalities:
single gene defects which cause disorders such as cystic fibrosis or Huntington's disease numerical chromosomal abnormalities (aneuploidy) which cause disorders such as Down syndrome (an extra chromosome 21) or Turner?s syndrome (females with one X-chromosome instead of two) structural chromosomal abnormalities such as various forms of translocations.
Who may want to use PGD?
PGD can be used by both fertile and infertile couples. Couples who are carriers of a familial single gene disorder may wish to access PGD to have children without the particular genetic disorder. PGD for aneuploidy screening can also be used for couples who are having trouble conceiving.
What are the potential benefits of PGD?
PGD offers people at high risk of transmitting a serious genetic condition to their children an alternative to their existing options of:
avoiding conception attempted natural conception, involving a known risk to the health of the future child attempted natural conception, and pregnancy termination if the fetus is found to be affected by the condition following prenatal diagnosis using donated gametes or embryos in an attempt to conceive an unaffected child.
For many people, termination following prenatal diagnosis is either unacceptable or less preferable because of:
ethical concerns based on beliefs about the moral status of the fetus emotional trauma associated with a termination, following a much desired pregnancy health risks associated with possible repeated terminations.
What are the concerns associated with the use of PGD?
PGD can only be used in conjunction with IVF. The ?take-home baby rate? for PGD is 20-30% per IVF cycle, which is similar to the live birth rate for IVF in the United Kingdom. Despite the relatively wide acceptance of PGD in the clinical arena, it remains a technically demanding procedure. It is subject to a risk of contamination and misdiagnosis, particularly when it is used for single-gene disorders. PGD involves the use of highly technical molecular biology techniques, the accuracy of which ranges from 96-99% depending on the type of test used. While PGD is diagnostically reliable, most European PGD clinics still advise their patients to undergo prenatal diagnosis to ensure that the preimplantation diagnosis is accurate and to test for any abnormalities not screened for during PGD.
Although many overseas PGD clinics offer aneuploidy screening to couples having trouble conceiving or carrying a baby, no consistent evidence is available to show that aneuploidy screening improves the live birth rate for couples having fertility problems.
What are the ethical issues associated with PGD?
Discarding affected embryos
PGD involves making a decision about the fate of affected embryos at a very early stage of development. This is in contrast to prenatal diagnosis, which requires a decision to be made about terminating an existing pregnancy at a much later stage. For many people, discarding embryos is likely to be ethically less problematic than terminating a fetus. For others, both abortion and PGD may be unacceptable.
PGD and disability
Some people suggest that PGD discriminates against people with disabilities, and promotes the view that the birth of people with disabilities should be prevented. However, others contend that it is important to distinguish between ?disability? and ?people with disabilities?, and that selecting against embryos with disabilities does not necessarily imply that those with disabilities are living lives that are less valuable or less meaningful.
Equity and access
Throughout the world PGD is an expensive procedure and concerns have been raised that the technology will be available only to the wealthy. Different jurisdictions have taken various approaches to public funding of PGD, with some governments not funding the service at all. Publicly-funded access to PGD in New Zealand will be considered by the Government after consultation on the PGD Guidelines has taken place.
PGD for Human Leukocyte Antigen tissue typing
Human Leukocyte Antigen (HLA) tissue typing or tissue matching is an additional step to PGD to determine if an embryo could lead to the birth of a child who is a tissue match for an ill sibling.
For some people, HLA tissue typing raises many ethical and social questions. One of the most significant issues is whether people should be able to select an embryo on the basis that the child born may be the source of life saving therapies for a sibling. Under the proposed PGD guidelines, any application for PGD with HLA tissue typing would need to be submitted to NECAHR for ethics approval.
Can PGD be used to select the sex of a baby?
Yes. The use of PGD for sex selection is carried out for two major reasons. The first is to prevent transmission of sex-linked genetic conditions such as haemophilia and Duchenne?s muscular dystrophy, when a specific test for the condition is not available. This medically-based rationale is acceptable to most.
The second reason, a social one, is to provide parents with a child of the preferred sex. This is seen as less acceptable for a number of reasons. Sex selection is seen as a demeaning reason for creating and discarding human embryos, in that it challenges the special status frequently bestowed upon them in view of the potential they represent. It is proposed that sex selection for social reasons be prohibited under New Zealand?s Human Assisted Reproductive Technology Bill.
Can PGD be used to ?design? babies?
In principle, PGD can be used to select for or against any characteristic that has a genetic origin. Some contend that PGD could be used to select against homosexuality, obesity, or hyperactivity, or for intelligence, beauty, or athletic ability. However, the use of PGD for these purposes is not currently scientifically possible.
The proposed guidelines for PGD will provide protection against potential misuse of the technology by prohibiting the use of PGD for non-medical reasons. In addition, the guidelines will allow PGD to be carried out only where there is a high risk of serious abnormality. For some, any selection of embryos is regarded as leading to designer babies. However, PGD does not allow people to determine the precise characteristics of embryos. The selection of embryos prior to implantation via PGD is selection from existing options rather than the design of babies.
Is PGD available overseas?
PGD was first carried out in 1990 for a couple at risk of having a child with cystic fibrosis. Internationally, PGD is employed clinically, and is available to those people who meet the required criteria, in a number of countries, including the United Kingdom, Australia, USA, Canada, Denmark, France, Belgium, Hungary, Sweden, Greece and Spain.
When will PGD be available in New Zealand?
After the consultation on the proposed PGD guidelines is completed in November, NECAHR will revise the guidelines where appropriate and send them to the Minister of Health requesting approval for them to be implemented. After the Minister approves the final guidelines, fertility clinics will be able to apply to NECAHR to offer the service in New Zealand.
How can I contribute to the consultation process?
NECAHR is seeking written submissions on the proposed guidelines for PGD. The consultation document and proposed guidelines for PGD are available on the Committee?s website (www.newhealth.govt.nz/necahr.htm). NECAHR is also holding public meetings in Dunedin, Christchurch, Wellington and Auckland to hear oral submissions at the end of November. Please indicate in your written submission if you would like to give an oral submission to the Committee. Written submissions must be received by 5:00pm Friday 12 November 2004.
Where can I get further information?
If you have any questions regarding the PGD guidelines or the consultation process, please write to the NECAHR Secretariat (email@example.com).