Probable involvement of immunoglobulin superfamily genes in most recurrent chromosomal rearrangements from ataxia telangiectasia.

From the chromosomal analysis of 9461 lymphocytes from 57 patients affected by ataxia telangiectasia, it is concluded that bands 7p14, 7q35, 14q12, and 14qter, which are frequently recombined in rearrangements are also too frequently involved in rearrangements with a few other chromosome sites. Among these sites, the most frequently involved are bands 2p11, 2p12, 22q12, and 22q13.2, or the proximal parts of adjacent R-bands. The same rearrangements were observed in a large series of control lymphocytes but their frequencies were much lower than in ataxia telangiectasia. All these recurrent sites of rearrangements, except 22q13.2, are known to be near or at immunoglobulin genes or partially homologous genes like T-cell receptor genes and antigen Leu-2/T8. It is supposed that the rearrangements observed correspond to the visualization at the chromosomal level of illegitimate rearrangements between these genes, and by analogy, that another similar structure may exist on band 22q13.2.