The fetal origins of childhood leukaemia

There is now compelling evidence that chromosome translocations are often the first events in the introduction or leukemia, the occurrence of prenatal fetal development. These findings come from two sources: identical twin infants or children with acute lymphoblastic leukemia agreed and retrospective control of neonatal blood spots. The most common structural genetic abnormality in childhood leukemia is a fusion of two genes, TEL and AML1. This is confirmed by a chromosomal translocation between chromosomes 12 and 21 Simultaneous breaks in the TEL gene (chromosome 12) and AML1 gene (chromosome 21), followed by errorprone repair, engravings, the DNA in the chromosomes 12 and 21, participate in the normally separate TEL and AML1 genes work together to a or chimeric fusion gene. As in other chromosomal translocations, the DNA breaks occur always in noncoding regions (introns) of genes. The precise breakpoints in the TEL-AML1 and can identify genes associated with or designated by the " long distance " polymerase chain reaction (PCR). Breaks always occur more or less randomly, in a limited region of these genes, but each patient & 39; of leukaemic cells have a unique (or clone-specific) breakpoint in the DNA sequence. Analysis of pairs of monozygotic twins agree with acute lymphoblastic leukemia shows that the leukemic cells from both twins in a few shares of the same breakpoints in TEL and AML1 gene, or in the case of twins child with acute lymphoblastic leukemia, the same stops in the MLL gene. Eineiigen twins are, of course, and even monoclonal genetically identical, but Gen-breakpoints in leukaemic cells are not inherited, they disappear into remission. The only plausible explanation for two leukemias in the same gene breakpoints is that the chromosomal breaks the generation of fusion gene has occurred only once, in a blood stem cell and a two-bed room in utero. Later, but still in utero, descendant offspring of these transformed cells, which are among the other twin, presumably on the anastomoses exist within single joint (monochorionic) placenta. We assume that in this early stage of a clinically silent, or hidden preleukaemic clone produced after birth, can affect full blown leukemia everything from two months to 14 years later. Further evidence that childhood leukemia can emerge from the birth control comes from the newborn blood spots or Guthrie cards. PCR tests for specific fusion genes for each patient, can detect as few as 120 leukaemic cells in the blood is a spot.
Cells4life umbilical cord blood bank.



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