Genes genetically altered in transitional cell carcinoma
| Gene (cytogenetic location) | Alteration | Frequency/clinical association |
|---|---|---|
| *Candidate genes; no tumour specific mutations detected to date. | ||
| LOH, loss of heterozygosity. | ||
| Oncogenes | ||
| HRAS (11p15) | Activating mutation | 10–15% overall (high grade)2–4 |
| FGFR3 (4p16) | Activating mutation | 30–40%5 6 |
| ERBB2 (17q ) | Amplification/overexpression | Amplified 10–14% high grade/stage7–11 |
| CCND1(11q13) | Amplification/overexpression | 10–20% all grades and stages12–14 |
| MDM2 (12q13) | Amplification/overexpression | Amplified 1–4%15 16 |
| Tumour suppressor genes | ||
| INK4A-ARF (9p21) | Homozygous deletion/methylation/mutation | 20–30% high grade/stage17–19 |
| LOH 60% all grades/stages | ||
| Immortalisation in vitro20 | ||
| RB1 (13q14) | Deletion/mutation | 10–15% overall21–23 |
| 37% muscle invasive | ||
| TP53 (17p13) | Deletion/mutation | 70% muscle invasive24–26 |
| High grade and stage | ||
| PTEN (10q23) | Homozygous deletion/mutation | 10q LOH in 35% muscle invasive27 28 |
| 6.6% superficial | ||
| PTCH (9q22) | Deletion/mutation | LOH 60% all grades/stages29 |
| Mutation frequency low | ||
| TSC1 (9q34) | Deletion/mutation | LOH 60% all grades/stages30 |
| Mutation frequency low | ||
| *DBCCR1 (9q32–33) | Deletion/methylation | LOH 60% all grades/stages31 32 |
| *DCC/SMAD (18q) | Deletion | LOH 30% high grade/stage33 |
| No mutation analysis to date | ||