Genetic tools offer the chance to eradicate hereditary diseases. Misused, they could become instruments for prejudice.

Eugenics has a dark history. In its simplest definition, it refers to the notion of improving the human gene pool through direct intervention. But the term brings up bad memories, as a movement arose in the early 20th century which attempted to 'purify’ the gene pool by forcibly sterilizing patients suffering from mental illness. It is seen as an unearthly practice that violates human rights and enshrines the idea of a 'perfect' individual. Recently, scientific developments have allowed us to read and edit DMA to an unprecedented scale and accuracy. This technology offers the chance to eradicate genetic diseases, while raising fears of ‘designer babies’, with physical traits that could be hand-picked by parents.

These fears have been brought about by two recent developments in the field of genetic engineering. Firstly, there has been a massive drop in the cost of DNA sequencing due to the adoption and increased commercialization of Illumina dye sequencing. In 2001, it cost around $100 million to sequence a genome. Nowadays, it can cost as little as $1500. Secondly, the advent of the CRISPR/Cas9 genome editing technique has allowed for researchers to edit DNA quickly, cheaply and effectively. It has been a breakthrough for scientists studying disease, allowing them to complete work in a few weeks that before would have taken them an entire year.

Researchers are already making big strides towards improving healthcare. Currently, pregnant women can undergo a procedure known as amniocentesis whereby a small dose of amniotic fluid is extracted to genetically test the fetal cells for chromosomal conditions such as Down’s, Edwards or Patau's syndromes. In fact, embryos created using in-vitro fertilization (IVF) can be genetically pre-screened to test for any chromosomal abnormalities, allowing doctors to select only those they deem fit to be transferred to the womb.

This procedure sparked debate when, in 2014, Richard Dawkins claimed that it is “immoral" to consciously choose to have a child suffering from Down’s syndrome. The Down's community hit back, with the advocacy group Saving Down's saying that it is right for parents to have a choice and that “there is nothing more demeaning to someone living with a disability than to be told that your life is of such little worth.

Additionally, with the use of CRISPR, scientists now have the tools to seamlessly change the genetic code in human embryos to weed out several harmful mutations at a time. However, there are concerns that editing the germline (the genetic code that can be passed onto subsequent generations) may be dangerous. In fact, Jennifer Doudna, one of the inventors of CRISPR, has called for a moratorium on editing the germline: “It is very important to consider the unintended genetic consequences of making an intended change, because there are all sorts of genetic interactions that occur in cells during cellular development, especially in humans but also other organisms as well.”

It may take many years until making genetic- changes to human embryos w ill be deemed safe. While many are excited by the technology's potential in eliminating disease, others are concerned by its power to summon up the demons of the past. It is foreseeable that, in the future, parents may be able to choose the personality and physical characteristics of their offspring according to their own prejudices.

Dystopic visions pop into peoples’ minds: a colorless future where everyone looks, thinks and acts the same. Some conjure up Brave New World, where the gulf between the rich and poor is exacerbated by genetic differences. Although at the moment this seems unlikely (as many traits, such as intelligence, are not controlled by a single, easily modifiable gene), many still oppose the use of genetic modification. The Economist remarks: “There are those who will oppose CRISPR because it lets humans play God. But medicine routinely intervenes in the natural order of things—saving people from infections and parasites, say.’’

Throughout recorded history, humans have been using tools to improve their lives. We have to ask, w'here does the line between medicine and meddling fall, and whose responsibility is it to decide?