[Retrospective Analysis of Genetics Abnormalities in Patients with Multiple Myeloma]

To explore the characteristics of cytogenetics and molecular genetics in patients with multiple myeloma(MM).

Fluorescence in situ hybridization(FISH) was used for molecular genetics analysis in 86 cases of newly diagnosed MM, at the same time the chromosome karyotype analysis was performed in 20 cases. Specimen were bone marrow cells.

FISH detection showed that 68 cases of MM (79.07%) had at least one type of the molecular genetic abnormalities. The positive rates of IgH rearrangement, 1q21 amplification, D13S319 deletion, RB1 deletion and.P53 deletion were 62.79%, 26.74%, 24.42% ,13.95% and 1.16%, respectively. The positive rate of IgH was significantly higher than that of any other probes(P<0.01). The positive rate of IgH was 79.41% in 68 cases. Out of which the positive rate of IgH single and combined with 1, 2, 3, 4 probes was 59.26%, 24.07%, 11.11%, 5.56% and 0 respectively. The positive rate of IgH only was very signficantly higher than that of combined with any other probes(P<0.01).The positive rate of 1q21 was 33.82% in 68 cases, Out of which the positive rates of 1q21 or combined with 1,2,3,4 probes was 21.74%, 43.48%, 21.74%,13.04% and 0 respectively, the 1q21 probe showed positive as combined with other probes(P<0.01), especially with IgH(P<0.05). The positive rates of D13S319 were 30.88% in 68 cases of patients, out of which the positive rates of D13S319 single or combined with 1, 2, 3, 4 probes was 14.29%, 28.57%, 42.86%, 14.29% and 0 respectively, the D13S319 combined with other probes appeared more significant positive(P<0.01), especially with 1 or 2 probes (P< 0.01). The positive rate of RB1 was 17.65% in 68 cases, the positive rate of RB1 singl or combined with 1, 2, 3, 4 probes were 0, 25%, 50%, 25% and 0, the RB1 appeared positive always combined with other probes, especially with D13S319 probe (P<0.01). The positive rate of P53 was 1.47%, as combined with RB1 and D13S319 probes. The chromosomal karyotyping showed that 3 cases carried abnormal chromosomal and 17 cases carried normal chromosome, Out of which 17 cases showed positive by FISH. There was a significant difference of sensitivity between FISH combined with chromosome karvotyping and single chromosome karvotype (P< 0.01).

The genetic abnormalies display obvious heterogenicity in MM. The sensitivity of FISH is higher than that of chromosomal karvotyping. If FISH and chromosome karvotyping are combined, the positive rate of abnormality can be raised.