Although some diseases occur when both copies of a gene are mutated, mutation of just one copy of certain tumour-suppressor genes promotes tumorigenesis. Identifying such mutations is arduous, but worth the effort. The myelodysplastic syndromes are thought to result from mutations in haematopoietic stem cells that result in the inefficient production of blood cells. Anaemia is a frequent manifestation, and patients often become dependent on red-blood-cell transfusions.
展开▼
