Characterization of a lymphoblastoid line deleted for lambda immunoglobulin genes

While characterizing the cat eye syndrome (CES) supernumerary chromosome for the presence of λ immunoglobulin gene region sequences, a lymphoblastoid cell line from one CES patient was identified in which there was selection of cells deleted for some IGLC and IGLV genes. Two distinct deletions, one on each chromosome 22, were identified, presumably arising from independent somatic recombination events occuring during B-lymphocyte differentiation. The extent of the deleted region was determined using probes from the various IGLV subgroups and they each cover at least 82 kilobases. The precise definition of the deletions was not possible because of conservation of some restriction sites in the IGLV region. The cell line was used to map putative IGLV genes within the recombinant phage λVλ135 to the distal part of the IGLV gene region. Since the deletions are relatively small, the cell line will be valuable for mapping IGLV genes in the distal part of this region.