Fourth International Workshop on Chromosomes in Leukemia 1982: Deletion of 5q.

In 36 cases with del(5q) examined, a type A2 deletion (q14 or q15q33) represented 56% of all cases, a type A1 deletion (q11 or q12q33) was present in 33%, and a type B deletion (q22q33) occurred in 11% of cases; therefore, all deletions were interstitial. The critical region for these cases was q22 to q33 or q34. Additional abnormalities were present in 85% of del(5q) cases; the most frequent additional abnormality was loss of one #7 (28%).