T-cell receptor delta gene rearrangement in childhood T-cell acute
lymphoblastic leukemia
A Biondi, E Champagne, V Rossi, G Giudici, A Cantu-Rajnoldi, G Masera, A Mantovani, TW Mak and MD Minden
Clinica Pediatrica Universita di Milano, Italy.
During the development of functional T lymphocytes, a variety of genes
involved in antigen recognition undergo somatic rearrangement. These
include the alpha, beta, and gamma chain genes. Recently a fourth
rearranging gene, the delta chain gene, embedded in the alpha chain locus,
has been described. We have determined the structure of the beta, gamma,
and delta chain genes in 15 cases of T-cell acute lymphoblastic leukemia
(T-ALL) representing stage I (CD7+, CD1-, CD3-) and stage II (CD7+, CD1+,
CD3-) of intrathymic T-cell development. The alpha-delta locus was
rearranged in 14 of the 15 cases. In three cases the delta constant region
was deleted on both chromosomes, suggesting biallelic V-J alpha
rearrangement. A limited pattern of rearrangement of the delta locus was
observed in the remaining 11 cases. When the alpha-delta region was
rearranged, there was rearrangement of the beta and gamma TcR in all cases
except two; in these cases the beta chain was in the germline
configuration. These findings support the hypothesis that delta chain gene
rearrangement is an early event in T- cell development, possibly
contemporary to gamma gene rearrangement, and that the delta locus has a
limited repertoire.
Volume 73,
Issue 8,
pp. 2133-2138,
06/01/1989
Copyright © 1989 by The American Society of Hematology
