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Team finds leukemia genes in Down kids

JIJI

Genes causing a type of leukemia that mainly strikes children with Down syndrome have been discovered by a team of Japanese researchers including Hirosaki University professor Etsuro Ito.

The finding, published in Sunday’s edition of U.S. science journal Nature Genetics, may help to develop a drug to counter the genes, the team said.

About 5 to 10 percent of perinatal infants with Down syndrome have transient abnormal myelopoiesis (TAM), a disease causing an abnormal increase in blood cells.

TAM is self-limiting in many cases, but 20 to 30 percent of patients develop potentially fatal acute megakaryoblastic leukemia (AMKL) within three years.

The research team found mutations in a gene related to blood cell proliferation in all 90 children with TAM or AMKL it collected samples from. Moreover, mutations were found in a gene related to cohesin complex, a protein complex that plays a key role in cell division, in 65 percent of the children with AMKL, the team said.

People with Down syndrome have three copies of chromosome 21, instead of the normal two.

TAM could occur as a result of interaction between the mutations in the blood cell proliferation-related gene and the abnormality in chromosome 21, which also has a gene associated with the multiplication of blood cells, the team said, adding that the mutations in the cohesin complex gene could lead to AMKL.