A woman suffering from cancer during pregnancy can pass the disease on to her unborn child, scientists have shown in a study that solves a puzzle that has perplexed doctors for a century.
The rare occurrence of a mother and child appearing to share the same cancer of which there have been about 30 known cases is a result of a genetic mutation that allows the cancer to pass to the baby undetected.
The scenario has baffled scientists by defying accepted theories of biology that suggest that even if a cancer were able to cross the placental barrier, it would be rejected by the babys immune system.
There was previously no genetic evidence to explain why a childs immune system would not recognise and destroy any invasive cancer cells that were of maternal and therefore, foreign origin.
The new study, led by Mel Greaves, of the Institute of Cancer Research (ICR), and published in Proceedings of the National Academy of Sciences, used advanced genetic fingerprinting to prove that an infants leukaemic cells were unquestionably of maternal origin.
The case, involving a Japanese mother aged 28 and her daughter, revealed that both patients leukaemic cells carried the identical mutated cancer gene BCR-ABL1 even though the infant had not inherited this gene.
This meant that the child, who had cancer diagnosed at 11 months old, could not have
