Designer Babies and Living Forever ((By Jade))

I have to put the brakes on my touch-down dance.   Yes.  I have finished final exams and lived to tell the tale, but Olivia is still chugging along.  So before we start knocking back egg nog (gross) and summarizing our semester, this is a fun post that stems from my not-so-fun final exam.

I recently completed a marathon of a final exam for Medical Genetics.  We had only a few days to devote to 7 mini-research papers on interesting and relevant topics in genetics.  I use the words interesting and relevant in retrospect, because, at the time, more appropriate descriptors were miserable and painful.  Anyways, I figured I would draw excerpts from the finished product and post some genetic predictions.

The questions were research-based but also incredibly open-ended.  The following are some meager genetic thoughts from my one-semester-brain-dead self in 2011:

 

On “exon-skipping” as a therapeutic measure and future implications…

 

Exon skipping is a method of treatment that intervenes at nonsense mutations.  These mutations are relatively common and account for about 11% of overall genetic mutations.  The same principle may be applied to abnormal splice sites or deletions, which similarly truncate the functional product.  Exon skipping involves modification of DNA translational activity to encourage newly-forming mRNA strands to “skip over” coding errors.

A 2007 article by Aartsma-Rus and van Ommen optimistically explained that, in principle, exon skipping would be corrective in any genetic disease that induces abnormal splicing.  I believe cystic fibrosis and DMD are popular contenders for research and treatment due to their relatively high incidences and the fact that they are reasonably well studied. In broader terms, exon skipping will only be applicable for diseases in which the pathogenesis is relatively well understood, long-term assessment has proven effective, and treatment does not produce off-target side effects (i.e. AON delivery to incorrect target tissues).  Uptake of treatment will be dependent on the benefits outweighing risks, which will take into consideration the price of treatments.

 

 

On “designer babies”…

 

Currently, we do not fully understand DNA.  It is estimated that 6% of the genome is still not sequenced, and our reference Human Genome only provides a rough blueprint of how we are put together.  It does not begin to explain the myriad of ways we can go wrong.  For example, in mice, researchers have shown that the addition of a certain gene made the mice better at running mazes, but also made them hyper-sensitive to pain (Steinbock, 2008).  Interestingly, in the previously cited article on music aptitude, researchers noted a correlation between the alleles linked to musical ability and a region previously associated with dyslexia (Puli, et al., 2007). To extrapolate, if we tweaked all the right genes to make someone the exact height, this might diminish their cognitive abilities – I do not believe we will ever have control over the catch-22 of genetics.

 

 

On aging as a “disease” (here I refer to telomere length on aging)…

 

To examine the degree to which senescence is genetically ordained, I researched examples of direct genetic links to age.  For instance, Progeria syndrome is a genetic disease that manifests characteristics of old age at very early ages and causes the body to produce dysfunctional progerin proteins.  It has been observed that fibroblast cells that use the defunct gene’s cryptic splice site have shorter telomeres, a finding associated with cell senescence (Cao, et al., 2011).  The notion of telomere length as a measurement of longevity is similar to the untimely death of Dolly, the first cloned sheep.  It is speculated that Dolly prematurely succumbed to disease because her telomeres were already aged significantly by the time she was born (Knight, 2011)…

To conclude the argument of genetically determined senescence, telomere investigation does suggest a finite division capacity of normal somatic cells, and genetic signaling pathways contribute to the speed of cell growth and aging.  Furthermore, the robustness of aging implies a strong genetic component and will prevent us from ever living as long as a tortoise.  The environment most likely interacts with our genetic blueprint to tweak the speed and manner in which we age.

 

 

In summary, no designer babies and no living forever.  If I’m wrong down the road, hopefully that won’t affect my final exam grade 🙂