Dr Kruskall believes the most likely explanation is that Jane's mother conceived non-identical twin girls, who fused at an early stage of the pregnancy to form a single embryo, according to a report published today in New Scientist.Thank you for providing a link to an article explaining a genetic chimera.For some reason, cells from only one twin dominate in Jane's blood - used for tissue-typing. In her other tissues, however, including her ovaries, cells of both twins live amicably alongside each other, hence the apparently impossible genetics of her three sons.
One son came from an egg derived from the twin whose cells dominate Jane's blood, while his brothers came from eggs derived from the other twin's cells