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Scientists Find New Leukemia Gene Risk Factors
By Kate Kelland, Reuters
January 10, 2010
LONDON (Reuters) – Researchers have found four new genetic variants that increase
the risk of contracting one of the major forms of leukemia, confirming that risk factors for
the fatal blood cancer can be inherited.
The findings mean scientists now know of 10 genetic variants associated with chronic
lymphocytic leukemia (CLL), scientists at Europe's Institute of Cancer Research who
conducted the study said.
The four new genetic factors are all common in European populations and each factor
contributes to an increase in the risk of the disease.
CLL is the most common type of leukemia in adults, accounting for around 30 to 40
percent of all forms of leukemia in Western countries. Most of those diagnosed are over
the age of 55, and while the incidence of CLL is broadly equal in black and white
populations, the disease is rare among Asians.
Richard Houlston, who led the study, said it confirmed the inherited risk of CLL, and
showed it was not due to a single gene due to the cumulative effect of many genetic
changes.
Each person may carry any number, from a few of the identified risk factors to all of
them, he said in research published in the journal Nature Genetics. And the more
genetic factors carried, the higher their risk of developing CLL.
"People who have more than 13 risk factors are seven times more likely than the general
population to develop CLL," Houlston added in a statement about the study.
The risk factors were identified using a genetic analysis technique that scientists have
used previously to find risk genes in breast, prostate, testes, brain and colon cancer and
childhood leukemia.
The researchers scanned the genes of 2,503 CLL patients and compared them to 5,789
healthy people, looking for differences in DNA between the two groups.
In previous studies, Houlston's team found that genetic factors could make people more
susceptible to CLL, identifying six genetic factors more common among sufferers.
The four new factors add to those findings and the study also found that 87 percent of
people with CLL would have at least one of these genetic risks.
David Grant, scientific director of the Leukemia Research charity which funded the
study, said it confirmed some long-held suspicions that this form of leukemia may run in
families.
"This research is providing the genetic evidence that an increased risk of developing
CLL can be inherited," he said in a statement.
"However it is clearly a complex picture and we need to study more families before we
can be certain of the particular genetic traits that are most important."
(Editing by Michael Roddy)
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