Malaysia needs stricter regulation of the genetic testing of embryos
DOWN syndrome is the most common genetic abnormality in newborns, and it is caused by the presence of an additional chromosome 21. As World Down Syndrome day approaches on March 21, we are reminded of the sobering statistic that around 90% of Down syndrome fetuses are routinely aborted worldwide.
The risks of Down syndrome rises with increasing maternal age, which is particularly significant for Malaysia, given the increasing trend of late motherhood in the country.
Currently, non-invasive prenatal testing of fetal DNA extracted from the mother’s blood is a reliable and accurate technique for diagnosing a Down syndrome fetus within the mother’s womb.
Genetic testing of IVF embryos
Undoubtedly, expectant couples undergo much emotional trauma upon receiving a positive Down syndrome diagnosis in prenatal testing, and face the agonising moral dilemma of whether to proceed with abortion.
For older women undergoing in vitro fertilisation (IVF) treatment, there is a way of avoiding this abortion dilemma by genetic testing of IVF embryos before they are transferred into the womb; this is done using a procedure known as preimplantation genetic testing for aneuploidy (PGT-A).
However, this procedure is highly expensive, tedious, time-consuming and invasive. There are risks of damaging the embryo upon extracting cells for testing. Many experts have pointed out that studies claiming no ill-effects from this type of testing are often based on excellent-quality, healthy, and robust embryos rather than more “delicate”, lower-quality embryos that might suffer more from the procedure. Hence, PGT-A poses greater risks for older women who tend to have lower-quality embryos.
Potential misuse of genetic testing
Despite its risks and high costs, PGT-A is widely marketed as a means of ensuring healthy births and avoiding Down syndrome fetuses for women undergoing IVF treatment, even though much cheaper and equally accurate prenatal testing methods are available. The major justification is to prevent the necessity of aborting a genetically-abnormal fetus, thus saving the expectant mother the medical risks and emotional trauma of abortion.
However, because genetic testing inevitably reveals the sex of the embryo (through identification of X and Y chromosomes), this would give IVF patients an opportunity to secretly select the sex of their embryos without any valid medical reasons.
In many traditional Asian cultures, there is often a strong social preference to have a son rather than a daughter, so as to have an heir to continue the family lineage and financially support parents in their old age. Hence, the need to prevent Down syndrome can readily be used as a convenient excuse and cover-up to use genetic testing for sex selection without valid medical reasons.
This raises serious ethical and moral concerns, as sex selection without valid medical reasons tends to reinforce sex discrimination and traditional gender stereotypes; it can also skew the population sex ratio as manifested in India and China.
Indeed, the guidelines of the Malaysian Medical Council on assisted reproduction explicitly prohibit sex selection of embryos for social or personal reasons.
AI-based embryo screening
Recently, a much cheaper and less invasive alternative to manual genetic testing of IVF embryos was announced by an American healthcare company. A novel artificial intelligence (AI) algorithm was developed that can accurately assess the genetic normality of IVF embryos based only on microscopy images.
Nevertheless, it must be noted that AI algorithms used to detect abnormalities can also be easily modified for sex selection.
This would be of even greater concern because such technologies are much cheaper and faster compared with manual genetic testing, thus making it more affordable and convenient for IVF patients wanting to do sex selection without valid medical reasons.
In the context of Muslim-majority Malaysia, a question that often arises in IVF treatment is whether Islam permits non-medical-based sex selection of IVF embryos for personal or social reasons. The dominant view among Islamic scholars is that non-medical sex selection is permissible provided there is a pressing need, the potential benefits outweigh the potential harms, and the sex selection method does not lead to abortion or infanticide. The most common example is a family with only daughters, that needs a son to continue the family lineage. Nevertheless, such a practice is not approved by the Malaysian Medical Council.
Unethical selection for non-medical-related traits
Polygenic testing for disease prevention can also be abused for selecting intelligence and other non-disease-related, socially-desirable traits
Another recent development is polygenic testing to estimate an individual embryo’s likelihood of developing adult-onset, multi-factorial traits such as obesity, type 2 diabetes and cardiovascular diseases by analysing the combination of specific genetic variants within its genome. This is referred to as preimplantation genetic testing for polygenic risk scores (PGT-P).
In a recent breakthrough, researchers in China used polygenic testing to select IVF embryos with less risks of developing family-related diabetes, for expectant parents with a family history of the disease.
Unlike the possibility of serious safety risks with gene editing, there are minimal risks involved in polygenic testing of IVF embryos because there are no permanent manmade genetic modifications that can be passed down to future generations.
Nevertheless, polygenic screening for complex multi-factorial diseases requires whole genomic DNA sequencing of IVF embryos, which at the same time can also be used for polygenic screening of various non-disease-related socially-desirable traits such as intelligence and athletic prowess as well as beauty standards such as tallness, fair complexion, and hair and eye colour.
This is a particularly lucrative business opportunity because parents naturally and instinctively want the best for their children. Indeed, a recent large-scale survey conducted in the United States showed that 38% of respondents indicated that they would use polygenic testing to improve their child’s IQ and academic performance.
Even if polygenic testing of IVF embryos for non-disease traits gets banned in Malaysia in the future, the fact remains that the genomic DNA sequence of IVF embryos will likely be available to patients who did polygenic testing for preventing diseases such as type 2 diabetes. It is difficult to deny such data to patients who pay for it.
These patients can freeze their DNA-sequenced IVF embryos, and send such data overseas for prediction of intelligence, tallness and fair complexion.
Psychosocial problems and social divides
The major ethical concern here is the fear of worsening social inequality, because only the rich can afford to use such expensive technologies to beget genetically advantaged children, while the poor will be excluded.
Over several generations of cumulative genetic enhancement, this may possibly lead to permanent stratification and divergence of humankind into genetically enhanced “haves” and “have nots”, which could in turn result in new forms of servitude and exploitation.
Additionally, there are also psychosocial problems. After spending so much money, parents may start having unrealistic expectations of their specially selected offspring. Children born through such procedures may have disturbing feelings of being treated like lab rats, and that their parents do not love them unconditionally as who they are.
Hence, there is a dire need for Malaysia’s Health Ministry to impose stricter regulations on new technologies for the genetic screening and selection of IVF embryos. In particular, there must be a clear boundary between embryo testing and selection to avoid serious harm from known genetic diseases and screening for non-disease-related, socially-desirable traits including sex selection without valid medical reasons.