Today afternoon when i heard of this professor from Human Embryology department will come and give a rare case presentation i couldn't resist my self left my shift na kwenda kumsikiliza ... it was about chemirism. What is Chemirism ? Simply the fusion of two or more human zygots. It may occur naturally during pregnancy, when two non-identical twins (even of different sexes) combine in the womb at a very early stage of development, such as that of the blastocyst, to form a single organism. Such an organism is called a tetragametic chimera as it is formed from four gametes - two eggs and two sperm. What Next? As the organism develops, the resulting chimera can come to possess organs that have different sets of chromosomes. For example, the chimera may have a liver composed of cells with one set of chromosomes and have a kidney composed of cells with a second set of chromosomes. This has occurred in humans, though it is considered extremely rare, but since it can only be detected through DNA testing, which itself is currently rare, it may be more common than currently believed. As of 2003, there were about 30 human cases in the literature, according to New Scientist. Mtu anaweza akawa bipolar "switch behavior " the way they talk, walk for 5-10min it is like you dont know them (bongo wanaweza wakasema ana pepo kichwani) but it might be ni pacha wake . have you ever heard/ seen this story "Iam my own twin" ? wewe hapo unaweza ukawa chemera but it needs a genitical test on different vital organs in you body. example DNA itakayopatikana katika Ulimi inatakiwa iwe sawa na ile inakayo kuwa tested katika maini. but on a chimera yeye anakuwa na DNA tofauti mfano. heart & liver might have different DNA`s as if they are from two different people. Physically unaweza ukajiangalia kwenye kioo mf. mzuri ni macho jicho la kushoto na kulia linaweza likiwa tofauti see this image bellow NB. kuwa na macho ya rangi tofauti sio confirmation test on chemirism. DNA test should be carried out. I am my own twin Lydia Fairchild and her children are the subjects of a documentary called The Twin Inside Me (also known as "I Am My Own Twin") Lydia Fairchild was pregnant with her third child, when she and the father of her children, Jamie Townsend, separated. When Fairchild applied for welfare support in 2002, she was requested to provide DNA evidence that Townsend was the father of her children. While the results showed Townsend was certainly the father of the children, the DNA tests indicated that she was not their mother. This resulted in Fairchild being taken to court for fraud for claiming benefit for other people's children or taking part in a surrogacy scam. Hospital records of her prior births were disregarded. Prosecutors called for her two children to be taken into care. As time came for her to give birth to her third child, the judge ordered a witness be present at the birth This witness was to ensure that blood samples were immediately taken from both the child and Fairchild. Two weeks later, DNA tests indicated that she was not the mother of that child either. back to our case seems like Lydia even though she was the one caring a fetus in her womb but that fetus was not hers . Walikuwa ni watoto wa twin wake ambaye haonekani but she wass inside her .. Lydia was a chimera. i couldnt finish this intersting lecture bcz niliitwa nirudi ward .. but nilikuwa na maswali mengi kichwani how does this happen bcz classically, the idea is that the placenta acts as a barrier between the mother and fetus to prevent mixing of the cells between the mother and fetus and to keep the mother's immune system from attacking the fetal cells. pia it's not quite that simple since the placenta is derived from the fetal cells. P.S - Nimeandika hii case bcz it is interesting ... do not take any medical advice inside this thread just keep in mind kwamba hivi vitu vipo even though ni rare 1/10000>>> For more info google the word chimera or go to www.nejm.org you will find a dozens of medical publications .