The Future of Gene Editing (CRISPR-Cas9)

(“CRISPR-CAS9” Podcast)

 

Might it become immoral to not genetically edit our children?

Perhaps it would be if there was an easy way to prevent disease, ensure health, and give them an overall better life.  If we knew of a way to improve their lives and we did nothing, does that make us somewhat responsible for their troubles?

This future may be closer than we think.

A new gene editing technology called CRISPR-Cas9 is revolutionizing the way we edit genes and has applications that we have only written about in science fiction.  This is not the first gene editing process ever invented but its speed and precision is what separates it from the rest.

Essentially, the process takes advantage of a natural process that the body already uses to combat viral infections and repurposes its function.  At the center of this process is a natural protein called Cas9.  Its natural function is to seek out viral DNA that is trying to invade a cells chromosomes and disable it by cutting the viral DNA in two.  It does this by linking up with a short piece of RNA that can identify the viral DNA by matching its genetic code.

(DNA is a double helix pair-based sequence.  However, RNA is has only one side of this sequence and thus searches for other strands to pair with.)

DNA RNA

 

Having an understanding of how this Cas9 protein operated, scientists then decided to attempt to give the Protein other segments of code to cut.  They soon realized that they can cut DNA from the cell’s chromosomes instead of the viral DNA.  By cutting a gene or even just parking the CAS9 protein on it, they could begin to turn on and off genes and observe the effects presented to the organism.  In this way we have been able to quickly map the function of genes.

CAS9 cut

Depiction of the CAS9 protein using RNA to link up with DNA and then make a cut.

However, the really interesting discovery came when they decided to cut the DNA in multiple places and replace the cut DNA with another segment of DNA.  By doing this they could alter or even completely replace certain genes.

This is where the applications of this technology really shines.  Remarkable genetic experiments have been done using similar technology to create glowing organisms through bioluminescence, create bananas that carry vaccines for disease, create mice that chirp like birds, and create cows that produce human milk.  Some of these may seem more useful than others.

We are crossing into a weird new territory.

All of these genetic manipulation experiments have been going on for some time but what CRISPR brings to the table is a much speedier and on the go adaptation of this technology.  Just last year, a group led by Shoukhrat Mitalipov at the Oregon Health and Sciences institute in Portland successfully edited human embryos to remove a heart condition that causes an increased thickness of the human heart, known as hypertrophic cardiomyopathy.  Anyone worried about the effects of having these “designer babies” can be assured that the embryos did not reach maturity.  US law prohibits any experimental embryos to be allowed to live for longer than 14 days after fertilization; a weird loophole all on its own. (See Radiolab podcast at bottom for more info.)

It is easy to imagine a future in which your first trip to the doctor after becoming pregnant is to have the full genome of your baby sequenced.  In 1990 it would have taken 13 years and cost 10 billion dollar to have your genome sequenced; today, it cost a couple thousand dollars and can be done in a day or two.  Most experts believe that, in a few decades, the sequencing of your genome will be a routine procedure and the whole field of medicine may shift to treat patients specifically to their genetic code.

So we will know our babies’ genetic codes.  Thus we will undoubtably know if our children have any sort of genetic disease almost immediately.  The CRISPR/Cas9 process now allows us to change that code to no longer be apart of our children’s DNA.  We could stop leukemia, growth defects, mental disorders, and other life threatening diseases.  If you knew your child had one of these diseases and did nothing, could that actually be the most immoral stance?  Many have argued that altering human genetics is a sin against the God who created us, but the truth is that we have been using all sorts of technology to overcome these genetic defaults for a long time now.  The eyeglass overcomes the genes for bad eyesight, insulin injections overcome the effects of diabetes, and vaccines even expose cells to non-active diseases so that then they can create antibodies that will recognize them in the future.

 

It seems like this genetic defense against disease and death is the next logical step.  And it may be that there will be a large group of people that believe it is wrong, but frankly those who take advantage of this technology will be the ones to survive.  This may sound harsh but unless there are some drastic side effects (which is possible and also why scientists  are very hesitant to roll these type of procedures out), then natural selection will favor those who take measures to ensure their survival.  This is not to say that everything that ensures survival is moral, but not ensuring the survival of you and your children does not seem to have any moral high ground either.designerbaby

But where do we draw the line?  Do we allow a person to give their children immunity to malaria?  Can people then give their children blue eyes, or bigger muscles, or a better IQ?

This slippery slope seems to lead us to a future much like that of the movie Gattaca, in which the elite are genetically modified to be better than those whose parents chose them not to be for either financial or moral reasons.  In the film, the characters refer to naturally born children as faith birthed.

 

But CRISPR/Cas9 process can expand beyond altering embryos.  There are applications of this technology that could alter grown organisms.  We could inject the Cas9 protein with a RNA sequence specifically designed to target cancerous DNA sequences and replace them, or we could inject Cas9 into mosquito populations making them unable to carry deadly diseases like malaria.  This technology is not only for the yet to be born but also for the already living.  But it is true that we must be carefull, that we should not get overly eager with our attempts to create a better world.  These techniques are not perfect.  The Cas9 is very accurate and degrades quickly so there is little chance that it could cut and replace the wrong gene but the chance of a mistake is not zero.  Although, for someone who is faced with the death sentence of irreversible cancer, they may still decide to take the risk.

But it does make one wonder, how long until gene editing is as common and mundane as the eyeglass?  How long until our DNA is not our own?

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By | 2018-03-02T14:53:47-08:00 February 26th, 2018|Biology, Featured, Science|0 Comments

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