[Cytogenetic profiles of follicular lymphoma]

To study the cytogenetic profiles of follicular lymphoma (FL) in Chinese patients.

Conventional karyotype in 57 FL patients from Shanghai area was analyzed. Fluorescence in-situ hybridization (FISH) for t(14;18) and Bcl-6 and IgH gene rearrangement was performed in these cases.

The most frequent breakpoints (frequency > or = 10% ) of the 57 FL cases were at band 14q32 (68.4%), 18q21 (38.6%), 3q27 (21.1%), 1q10 (15.8%) and 1q21 (12.3%). Nineteen (33.3%) of the 57 cases had t(14;18). The breakpoint of 18q21 and t(14;18) were more frequent in FL grade 1-2 and less frequent in FL grade 3 (57.6% vs. 12.5%; 54.5% vs. 4.2%, P < 0.05), whereas the 3q27/Bcl-6 rearrangement was more frequent in FL grade 3 and less frequent in FL grade 1-2 (37.5% vs. 9.1% , P < 0.05). The cohort of FL was more frequent in gains of chromosomes X, 1q, 5, 6p, 7 and 12q and losses of chromosomes 1p, 6p and 14q32. Gain of 18q was more frequent in FL grade 1-2 than in FL grade 3 (P < 0.05). Loss of 14q32 was more frequent in t(14;18) negative FL than in t(14;18) positive FL (P < 0.05).

Compared with the data of Western patients reported in the literature, Chinese FL cases had distinct cytogenetic profiles from Western FL cases that the t(14;18) is less frequent and the gain of 1q is more frequent in Chinese FL cases, which are more significant in high grade FL.