We have characterized immunophenotypically defined acute lymphoblastic leukemia (ALL) in Egypt for rearrangements of the antigen receptor genes, and correlated this with rearrangements of ALL-1 and the presence of p53 mutations.
Thirty-nine cases were analyzed for rearrangements of the immunoglobulin (Ig) and T-cell receptor (TCR) genes.
All precursor B-cell ALLs (12 cases) contained rearranged Ig heavy-chain (JH) region which was biallelic in 92% of these tumors.
In addition to JH rearrangements, TCRdelta, bêta and gamma rearrangements were observed in 80,40 and 30% of these cases, respectively.
TCR genes were invariably rearranged in T-cell ALLs (11 cases).
A small fraction (2/11) of T-cell ALL showed concurrent IgJH rearrangement which was monoallelic.
Simultaneous rearrangement of IgJH and TCR genes was also observed in both cases of biphenotypic ALL (coexpressing B and T markers).
We observed marked heterogeneity in the pattern of rearrangement of antigen receptor genes in mixed-lineage leukemias (ALL coexpressing myeloid-associated markers), including the retention of germline configuration in two cases.
Rearrangements of the ALL-I gene were confined to the leukemias that demonstrated lineage infidelity.
Mutations in p53 were infrequent and were present in only three of 47 ALL cases (6%) analyzed ; two of these were mixedlineage leukemias.
Mots-clés Pascal : Leucémie lymphoblastique, Gène suppresseur tumeur, Mutation, Immunoglobuline, Gène, Récepteur cellule T, Lymphocyte T, Réarrangement génique, Phénotype, Epidémiologie moléculaire, Egypte, Afrique, Homme, Aigu, Hémopathie maligne, Lymphoprolifératif syndrome, Gène p53
Mots-clés Pascal anglais : Acute lymphocytic leukemia, Tumor suppressor gene, Mutation, Immunoglobulins, Gene, T cell receptor, T-Lymphocyte, Gene rearrangement, Phenotype, Molecular epidemiology, Egypt, Africa, Human, Acute, Malignant hemopathy, Lymphoproliferative syndrome, p53 gene
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0192347
Code Inist : 002B19B. Création : 09/06/1995.