From Cancer to the Common Cold, How Your DNA determines your risk
By Jay P - February 24, 2013
We all have that person who seems like they are always sick. Science has recently discovered that it may be more than just a bum immune system but may boil down to the building blocks of life, DNA via telomere length. For everyone who slept though high school biology, Telomeres are an essential aspect of human biology. But before we say why, lets get down to what a telomere actually is.
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| A chromosome that is capped by the telomere |
Human beings are made up of DNA, which is the building blocks of all life. Within the cells inside of our body, the DNA is wrapped into super-coiled structures called chromosomes. Each of the millions of cells within the human body consist of 46 chromosomes, that translates to 23 chromosomes inherited from your mother and 23 chromosome inherited from your father = 46 chromosomes (23 pairs of chromosomes).
Here is where it gets interesting, chromosomes are super-coiled DNA structures, however the ends of chromosomes are capped by DNA repeats known as telomeres. Believe it or not telomeres determine the destiny of the cells within your body. Specifically, every time a cell divides within your body the telomeres are reduce, and there are only a finite number of divisions that a cell can undergo before it becomes depleted in telomeres and stops dividing.
Interestingly enough, the role of telomeres has been linked to cancer for several years. When normal cells run out of telomeres they cease to divide. Therefore by overcoming telomere depletion cancer cells avoid a crucial road block in the pathway to cancer initiation and progression as cancer cells have an infinite mitotic division potential and will continue to divide as long as possible.
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| Chromosomes capped by telomeres (23 pairs of chromosomes) Image: WIKIMEDIA COMMONS/NATIONAL HUMAN GENOME RESEARCH (user GIAC38) |
A recent study by researchers from Carnegie Mellon University has also linked telomere sturcture and function to the susceptibility of individuals to contract the common cold also known as the Rhinovirus. This study found that individuals >20 years old with shortened telomeres were more susceptible to contraction of the common cold than individuals with the longer telomeres. This may be due to the mechanism of infection of viruses that integrate into the DNA of the host. Therefore, shortened telomeres may aid in the mechanism of infection of the rhinovirus (common cold).
For a long time we have associated susceptibility to the common cold with dietary and nutrient factors such as Vitamin D, Vitamin C, Zinc etc. And yes factors like sleep deprivation are an important factor to susceptibility to the common cold. However, this study suggest that although we have a thorough understanding of susceptibility to foreign pathogens and the role our immune system plays in this process, our genetics may play just as crucial a role in our ability to contract and fend off diseases/pathogens.
The moral of the story is that our genetic signature is more influential in our health outcome than we ever suspected. So don't discount your DNA!
photo credit: telomeres chromosomes
photo credit: capped chromosome
photo credit: telomeres chromosomes
photo credit: capped chromosome
