November 29, 20192
In 1953 a human chimera was reported in the British Medical Journal. A woman was found to have blood containing two different blood types. Apparently this resulted from her twin brother’s cells living in her body. A 1996 study found that such blood group chimerism is not rare.
In animals, chimerism is quite common and in humans not as uncommon as previously thought.
Chimerism is a condition whereby a person has not one but two complete genomes (sets of DNA) in their body. One genome is found in one region or organ(s), while the other genome can be predominant in other organs or tissues.
This is from Mixed field reactions in ABO and Rh typing chimerism likely resulting from twin haematopoiesis:
What is also more common than previously known of is a vanishing twin syndrome. One consumes all of the resources usually and the other weaker one dies. A sense of survivor’s guilt is what many surviving twins feel for a reason.In conclusion, this case identified a case of a permanent genetic chimera resulting from twin-twin exchange of genetic material in utero. Suspicion for the presence of a chimera was initially prompted by the findings of an ABO and Rh discrepancy on a routine pre-transfusion sample. Additional questioning uncovered the existence of a deceased twin. Further characterization of the discrepancy was achieved in a reference laboratory, including a demonstration of the use of flow cytometry to delineate and quantify the presence of two distinct cell populations.
Have you ever noticed how so many celebrities and those who can afford excellent health care tend to have a lot of twins?
Of the 4 major reasons why blood type tests can show different results, chimerism is at the lower end. Human error is the main reason.
If you or someone you know has this phenomenon, feel free to comment.
Thanks to: https://www.rhesusnegative.net