Left-Right Asymmetry

In my search for a possibly interesting application of symmetry in real-life, I came across a study on the symmetry of cells to help prevent birth defects [1]. What particularly caught my attention was the term “left-right asymmetry”. Basically, it is involved with the question of how our internal organs are positioned during embryonic development–how does the bilaterally symmetric embryo decide which is left/right and which is the correct side for an organ? [2]

This is how I learned that 0.01% of our population has the condition called situs inversus totalis, where there is a mirror-image reversal in the positioning of the heart and other internal organs. [3] People with this condition don’t usually realize their unusual anatomy until they seek medical attention for other health problems not related to it. This usually causes confusion because many signs and symptoms appear on the reverse side. [4]

This condition also happens to “mirror twins”–twins who have the same physical features but opposite, or “mirrored”. [5]

It is usually complicated for people with situs inversus totalis to undergo heart transplants because the orientation of the heart is reversed and it is necessary to connect the blood vessels properly.

[1] https://www.sciencedaily.com/releases/2014/03/140320173204.htm
[2] http://rsob.royalsocietypublishing.org/content/3/5/130052
[3] https://en.wikipedia.org/wiki/Situs_inversus
[4] https://pdfs.semanticscholar.org/1585/aa045be15764f8a863cc94a42970139dfc33.pdf
[5] http://www.twin-pregnancy-and-beyond.com/mirror-twins.html

Images from:
http://www.ohmyindia.com/ (situs inversus totalis)
http://marlafoundation.org/ (twins)