Table 3.
Types of genotyping errors reported in KRAS testing
| EQA year and Run |
Number of laboratories reporting genotyping errors (%) | Total number of errors reported | False positive results reported | False negative results reported | Incorrect mutation reported | aExtra mutation reported (not present) |
|---|---|---|---|---|---|---|
| 2009 | 1 (5.5) | 1 | 0 | 1 | 0 | 0 |
| 2010 | 2 (4.9) | 5 | 1 | 2 | 2 | 0 |
| 2011–2012 Run 1 |
5 (9.8) | 8 | 0 | 7 | 1 | 0 |
| 2011–2012 Run 2 |
2 (4.2) | 8 | 1 | 1 | 6 | 0 |
| 2011–2012 Run 3 |
5 (9.6) | 5 | 0 | 3 | 2 | 0 |
| 2012–2013 Run 1 |
3 (5.2) | 4 | 2 | 2 | 0 | 0 |
| 2012–2013 Run 2 |
1 (1.5) | 1 | 1 | 0 | 0 | 0 |
| 2012–2013 Run 3 |
2 (3.0) | 2 | 0 | 2 | 0 | 0 |
| 2013–2014 Run 1 |
2 (3.4) | 3 | 1 | 2 | 0 | 0 |
| 2013–2014 Run 2 |
2 (3.3) | 2 | 0 | 2 | 0 | 0 |
| 2013–2014 Run 3 |
4 (6.3) | 4 | 0 | 2 | 2 | 0 |
| 2014–2015 Run 1 |
9 (10.7) | 15 | 8 | 6 | 1 | 0 |
| 2014–2015 Run 2 |
14 (16.7) | 16 | 2 | 12 | 1 | 1 |
| 2015–2016 Run 1 |
13 (13.1) | 25 | 8 | 11 | 6 | 0 |
| 2015–2016 Run 2 |
7 (6.5) | 11 | 8 | 1 | 0 | 2 |
aExtra mutations differed to a false positive result, as these mutations were detected in addition to the mutation actually present in the sample, rather than being detected in a wildtype sample, which was classed as a false positive result