When we hear of genetic screening, many of us think of screening newborns for rare, inherited conditions such as cystic fibrosis. It seems miles away from science fiction depictions of babies being genetically engineered.
But maybe we’re not too far away from science fiction becoming science fact. After all, the Human Genome Project’s sequencing of the human genome (our entire genetic code [DNA]) was completed more than a decade ago (in 2003).
A handbrake on progress in genetics back in the days of the Genome Project was simply the time it took to sequence DNA (if you think of DNA as a book, the human genome is about 3 billion letters [base-pairs] long). Ten years ago, it took several years and about $10 million USD to sequence a human genome.
Today, it costs about $1,000-2,000 (excluding analysis and interpretation) to sequence a genome and it’s getting cheaper and faster all the time.
But thanks to the development of the “massively parallel sequencing” (or next-generation sequencing), we sequence more, faster, for less money. Today, it costs about $1,000-2,000 (excluding analysis and interpretation) to sequence a genome and it’s getting cheaper and faster all the time.
This means that routine genomic sequencing, or screening the whole of your genetic information (DNA), is possible, not just looking at one or two genes at a time as in the genetic screening of the past. But genomic screening is not yet approved in Australia, outside of research.
Before this happens, governments need to establish how best to use this powerful tool. The Melbourne Genomics Health Alliance of universities, hospitals and research institutes, formed in 2013, is one example of the attempt to develop new genomic tests, evaluate their usefulness and bring them into mainstream health care.
The enormous potential of rapid genomic screening in medicine is already being demonstrated: a group at the Children’s Mercy Hospital in Kansas City is conducting studies where the genomes of critically ill newborns are screened very rapidly (in less than 24 hours) in order to find out what is wrong with them and save lives.
We can now screen babies much more easily for genetic problems before they’re born; as of 2015, it’s possible to screen foetal DNA by maternal blood test — the “non-invasive prenatal test” (NIPT).
We can now screen babies much more easily for genetic problems before they’re born; as of 2015, it’s possible to screen foetal DNA by maternal blood test — the “non-invasive prenatal test” (NIPT). Until now, an invasive test (amniocentesis) involving a large needle and small risk of miscarriage was required. Embryos can also be screened for more than 100 genetic diseases using preimplantation genetic diagnosis (PGD), which means fertile at-risk couples can combine IVF and PGD to select embryos free of these diseases.
In these cases, babies are already selected based on their DNA to an extent. In the US, this is taken further: the Fertility Institutes let parents choose the sex of their IVF baby.
In the field of preventive medicine, the potential of genomic screening is huge. Genetic tests already hint at what the future could bring. Hollywood star Angelina Jolie underwent a genetic test which showed she had a mutation in one of her BRCA genes, making her at high risk of developing breast cancer. She chose to have a double mastectomy to reduce the risk. But although we can now test for more than 1,000 rare genetic conditions, the problem is only a tiny fraction of the genetic variants contributing to risk for common but more genetically complex diseases such as diabetes are known.
Genomic screening would allow us to look at many genes at once and would increase the power and scope of predictive tests in future. We might also be able to tailor medicines to people based on their genetics.
Our genes determine how we respond to drugs. A genetic test is done to make sure HIV patients don’t have a mutation which would cause them to have a bad reaction to the drug Abacavir. Genomic screening would allow us to look at many genes at once and would increase the power and scope of predictive tests in the future. We might also be able to tailor medicines to people based on their genetics. For instance, cancers people develop vary widely depending on their genetic makeup.
The International Cancer Genome Consortium (which includes Australia) is sequencing cancer genomes to eventually enable targeted treatments to be developed for different types. Personalised medicine will be progressively refined as our knowledge increases.
Another emerging technology — gene therapy — might be used in the future to correct faulty genes identified in a screen. Gene therapy is about supplying your cells with a working copy of a faulty gene. Getting genes into the right spot in the right cells without disrupting anything is challenging.
In 2015, treatment will begin with the first gene therapy ever approved in Western countries: Glybera treats a rare genetic condition called lipoprotein lipase deficiency via a modified virus which delivers a working gene into the body’s cells.
As for designer babies, genetic modification of embryos in order to prevent rare diseases has already been approved in the UK. This was done to save lives.
And here’s where science meets science fiction: the combination of genomic screening with gene therapy means you could theoretically tinker with your genes to change yourself — not just to cure disease — but in any way you want.
As for designer babies, genetic modification of embryos in order to prevent rare diseases has already been approved in the UK. This was done to save lives. But the possibilities don’t end there. What if one day you could give your baby better genes for intelligence or good looks?
Turns out, many are in favor of the natural genetic process. Given the option to choose one or more traits for a child, only 40 percent of Budget Direct’s survey participants said they wouldn’t.
Challenges & Implications
The reality is that engineering or screening for super-babies is long way off. There is a huge gulf between what we can do (sequence our genome) and what we know (what the genome does).
Should we use genetic technologies to design babies or redesign ourselves? If we start altering the natural variation in the human gene pool, would that affect the future of the race? What genetic tools bring us depends on how we use them, and with what intentions. The scope for discrimination against people based on their genetics is enormous.
The prominence of eugenics in cult classics like “Doctor Who”, “Star Trek” and “Gattaca” warn us of the extremes. Public debate is needed before genomic technologies are used for anything but clear medical benefit.
The reality is that engineering or screening for super-babies is a long way off. There is a huge gulf between what we can do (sequence our genome) and what we know (what the genome does). Working out what genes do is enormously complex. For instance, it is very unlikely that IQ depends on a single “intelligence gene” but rather the interplay of many genes currently unknown.
It’s not simply a matter of knowing who the players are, but how they interact. Genes can also have multiple roles, even opposite roles depending on the situation. And then, there’s the environment: identical twins (with the same genetic material) don’t grow up to be the same person. This shows how important your environment is in determining who you are.
The variables involved are enough to give a supercomputer a headache. Literally. Supercomputers are used in trying to work out how our genome works. Our complete understanding of the genome is still a long way off. If we’re lucky, it’ll be long enough for us to learn how to use it wisely.
International Human Genome Sequencing Consortium (2004). “Finishing the euchromatic sequence of the human genome”. Nature 431 (7011): 931–45.
Survey Stats: Survey was conducted by Budget Direct in the month of April 2015 with a random selection of 1,000 people.