Translocations involving 9p and/or 12p in acute lymphoblastic leukemia. United Kingdom Cancer Cytogenetics Group (UKCCG).

Fifteen cases of acute lymphoblastic leukemia (ALL) with translocations involving 9p and/or 12p are described. Four children, three males and one female, age range 1-8 yrs, had translocations involving 9p but not 12p. Of these, three had B-lineage ALL and one had biphenotypic T-ALL/acute myeloid leukemia. Six patients, three males and three females, age range 1-49 yrs, had translocations involving 12p but not 9p. Five had B-lineage ALL and one had T-ALL. One patient had dic(7;12)(p11;p11), confirming that this previously reported translocation is nonrandom in ALL. One patient had t(2;12)(q14;p13), and it is suggested that this may also be a new nonrandom abnormality. Five patients, four males and one female, age range 11-21 yrs, had common ALL and dic(9;12). The dic(9;12) appears to confer a better prognosis than do other translocations involving 9p or 12p.