Table 2.
PIK3CA Gene Variants in Breast Cancer (FFPE) Samples, as Detected by HRMA, and Defined by DNA Sequencing
| Nucleotide change | Protein change | Number of samples | Relative (%) | Total (%) |
|---|---|---|---|---|
| Validation group | ||||
| Exon 9 | ||||
| c.1633G>A | E545K | 6 | 18.8 | 6.1 |
| c.1624G>A | E542K | 2 | 6.2 | 2.0 |
| c.1636C>A | Q546K | 2 | 6.2 | 2.0 |
| c.1633G>C | E545Q | 1 | 3.1 | 1.0 |
| c.1634A>C | E545A | 1 | 3.1 | 1.0 |
| Exon 20 | ||||
| c.3140A>G* | H1047R | 19 | 59.5 | 19.2 |
| c.3140A>T | H1047L | 1 | 3.1 | 1.0 |
| Total | 32 | 100 | 32.3† | |
| Selected group | ||||
| Exon 9 | ||||
| c.1633G>A | E545K | 3 | 9.7 | 4.0 |
| c.1624G>A | E542K | 2 | 6.5 | 2.7 |
| c.1636C>G | Q546E | 1 | 3.2 | 1.3‡ |
| Exon 20 | ||||
| c.3140A>G | H1047R | 23 | 74.2 | 30.7 |
| c.3140T>G | H1047L | 1 | 3.2 | 1.3 |
| c.3136G>A | A1046T | 1 | 3.2 | 1.3‡ |
| Total | 31 | 100 | 40.0ठ|
*
One fibroadenoma sample, found to bear this mutation, is not included.
†
Of the 99 tumor samples.
‡
The two mutations c.1636C>G and c.3136G>A were detected in the same sample, and therefore counted as a single mutated sample.
§
Of the 75 tumor samples.