Multiple Myeloma: Chromosome 1q+ cytogenetic abnormalities
.webp/jcr:content/oncology-ta-banner%20(1).webp)
Multiple copies of chromosome 1 (1q+) is a frequent CA in MM
- MM is characterized by CAs in plasma cells1
- Frequent gains include 1q, 6p and 11q1
- 1q+ is one of the most common CAs in MM
.webp)
1q+ abnormalities are defined by copy number
Chromosome 1q abnormalities terminology3

+1q | Additional copies of any part of the long arm of chromosome 1 (1q), irrespective of copy number or DNA segment gained |
Gain(1q) | Gain of only 1 extra copy of chromosome 1q (3 total copies) |
Amp(1q) | “Amplification” of 1q, with 2 additional copies of chromosome 1q (4 or more total copies) |
In MM, 1q+ is frequently denoted as 1q21+, which refers to a specific location – region 2, band 1 on the long arm of chromosome 1
Overexpression of certain genes in the 1q arm may drive pathogenesis and drug resistance4,5

Key genes located in the 1q21 band:
| Resistance to PIs through the upregulation of the proteasome genes, including PSMD6 |
|

Other key genes outside of the 1q21 band include:
| Resistance to drugs that rely mainly on CDC through upregulation of complement inhibitors, such as CD557 |
|
1q+ terminology when co-occurring with/without other high-risk cytogenetic abnormalities (HRCA)8
.webp)
1q+ increases throughout the MM disease course4,9

Prognosis worsens with increasing copy number

Incorporating 1q+ testing into clinical practice remains challenging

New staging systems, such as R2-ISS, MASS and R-ISS-1q,12–14 are including gain/amp(1q), alongside other high-risk factors when defining disease stage, in order to refine predictions of clinical outcomes and highlight the prognostic impact of gain/amp(1q)
Although most guidelines include 1q+ in their HRCA definitions, the recommendations for FISH panel testing for 1q+ are inconsistent and there is little treatment guidance specific to gain/amp(1q)15–17