Jan. 20, 2013 Research led by St. Jude Children's Research
Hospital scientists has identified a possible lead in treatment
of two childhood leukemia subtypes known for their dramatic loss
of chromosomes and poor treatment outcomes. The findings also
provide the first evidence of the genetic basis for this high-
risk leukemia, which is known as hypodiploid acute lymphoblastic
leukemia (ALL). Normal human cells have 46 chromosomes, half
from each parent, but hypodiploid ALL is characterized by fewer
than 44 chromosomes. Chromosomes are highly condensed pieces of
DNA, the molecule that carries the inherited instructions for
assembling and sustaining a person. The research appears in the
January 20 advance online edition of the scientific journal
Nature Genetics. The study, the largest ever focused on
hypodiploid ALL, confirmed that this tumor has distinct subtypes
distinguished by the number of chromosomes lost and the
submicroscopic genetic alterations they harbor. Researchers
found evidence suggesting more than