A Game of Genetics

The other day I managed to fall off my bike. It was quite a spectacular fall where I flew straight over the handlebars and landed rather ungracefully onto my shoulder and back. While worried strangers were attempting to untangle me from my mess, my head was running through where potential pain was coming from. Luckily I managed to survive without breaking a bone and with only a few bruises and my pride dented I cycled off.

Today I have been in pain and while taking multitudes of pain killers it got me thinking what must it be like not to feel pain? A very rare genetic disorder known as congenital analgesia means that sufferers cannot feel any physical pain. While this might sound like a beneficial thing if you are clumsy like me, it is actually an extremely dangerous genetic disease and is one of many that the medical field are still struggling to treat effectively.

Recently I attended the Haldane lecture at the Royal Institution, which was given by my supervisor Alison Woollard, where she spoke about the Genetics Revolution. She presented seven sub-revolutions in genetics that have been ground breaking in the field, but it was her seventh and final revolution really caught my attention. This is the revolution of genome editing using the CRISPR-Cas9 system.

This technique makes use of the natural immune defences of bacteria, whereby the Cas9 protein, guided by synthetically made guide RNA, can be delivered to sections of DNA and can cut them out with extremely high precision. Genetic modifications can then be introduced into the genome, for example a knockout of a gene.

The relevance of this discovery for me as a potential medic is enormous. This system has such huge potential for the treatment of genetic disease that currently affects a significant number of individuals in our population, including those suffering from diseases like congenital analgesia. What will seriously need to be considered for the future of this treatment are the ethical issues that surround it and will require contribution not only from the medical field, but also the population as a whole.

Take the disease genetic cystic fibrosis. It is the result of a homozygous autosomal recessive mutation in the gene for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. As only a single gene causes there is huge potential for systems such as CRISPR-Cas9 to be able to cure this disease, which causes so much suffering to its patients.

The ethical considerations that a medic might face were this treatment to remain in the somatic cell line are perhaps much less complicated than the considerations that are faced were the treatment to be used in the germline. Treatment to the somatic cell line will mean that the sufferer will be cured, but they will still be able to pass on the recessive gene to their offspring and then their children’s offspring and so on.

Genomic editing of the germline is something that fascinates me, excites me and frightens me all at the same time as a future medic. It has the power to eradicate genetic disease such as cystic fibrosis, which can only be a good thing, but are we going too far? By messing with the germline we are changing the lives of not only the patient, but also their children. Is this ‘playing God?’ How far would the medical world be willing to go with germline editing? Are designer babies potentially on the horizon for humanity?

Of course I appreciate that altering a persons intelligence is a far cry away from the treatment of a genetic disease, in addition to the fact these traits are the result of multiple genes, but who is to say that this is a debate that medics and alike are having to make in the future?

I expect it might.