Immunoglobulin (Ig) and T-cell receptor (TCR) genes were examined in the lymphoblasts of 70 children with immunophenotypically defined B-cell precursor acute lymphoblastic leukemia (ALL).
TCR-delta rearrangements or deletions were found in all T (33 cases) and B lineage (28 cases) ALL but not in any case of B cell chronic proliferations (13 cases).
The most immature B lineage ALL ('null' ALL) has a much lower frequency of TCR gene rearrangement than the common variant of B cell precursor ALL and also has a high frequency of oligoclonal rearrangements of IgH genes.
T cell rearranging gene gamma (TRG gamma) and T cell antigen receptor beta (TCR beta) chain gene rearrangement and transcription were studied in a series of patients with B-lineage acute lymphoblastic leukemia (ALL), in which the Ig H chain genes are rearranged and the surface phenotype reproduces the stages of normal pre-B maturation.