Did you hear the story of the man who was his own child’s uncle?

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This sounds like a joke, but really truth is stranger than fiction. A couple in America wanted a child and things didn’t seem to be working out so they went to a fertility clinic for help. This was successful and they had a healthy child and all was well – until by chance they discovered that the child had a blood group that was unexpected based on those of his parents, and this suggested that the man was not the real father. Since the baby had been born as the result of assisted reproduction, the parents suspected that the clinic had messed up and used a sample from another man. But the clinic claimed that he was the only Caucasian man who had donated on that date, and the child appeared to be Caucasian, so they couldn’t possibly be in the wrong. To cut a long story short (well, a bit), initial DNA tests had taken samples of DNA from the father’s cheek, a common and easy way to collect a sample of cells, but of course these were not the same cells as had been used to create the baby, and eventually the results of more rigorous testing revealed that the father had different DNA in some of the cells of his body from others – he was a genetic chimera. What must have happened was that the father, when he was an embryo just beginning to develop in his own mother’s womb, had actually been formed by the fusion of two fertilized egg cells. When an egg is just beginning to develop into an embryo, it divides into two, then four, then eight cells and so on up to 32 cells and each of those cells has the potential to form any organ in the body. So when two eggs fused, they each divided as usual and their progeny were interspersed and were incorporated into different organs throughout the child’s body. Imagine it as the opposite of the formation of identical twins; instead of one fertilized egg splitting into two, two different fertilized eggs fused to form one person, and instead of non-identical twin brothers, only one baby was born but he carried the DNA from two different individuals. This is the first documented case of its kind, although two mothers have previously been identified in similar cases. No-one knows how common this situation is; it could actually be far from rare but until recently the technology has not been available to identify affected individuals, and in most cases there has been no reason to test for it. Life really is strange and fascinating and gets more so the more we find out about it! All rights reserved. © copyright Fleur 2015.