Inherited risk factors for common leukaemia

Scientists have produced the first unequivocal evidence for inherited factors that contribute to susceptibility to chronic lymphocytic leukaemia (CLL), reports a paper published last week in Nature Genetics. Approximately 25% of all individuals with leukaemia have this form of the disease.

CLL results from the abnormal proliferation of B cells – a type of white blood cell that originates in the bone marrow. While it is known that individuals with a family history of CLL are at higher risk, the genetic basis of this risk has not been defined.

Richard Houlston and colleagues carried out a genome-wide association study of individuals with CLL, followed up by replication attempts in two additional groups. They found six common variants that modestly increase risk of the disease. Three of these variants are in or near genes that are good candidates for involvement in CLL, based on their known functions in B cells. Individuals with all six variants are estimated to have an eightfold elevated risk of disease. The authors suggest that these variants may influence the risk of other disorders of B-cell proliferation as well.