Last update: 05/06/2006
Background to disease
|
Subtype |
1 |
2 |
3 |
4 |
5 |
MTS* |
|
OMIM # |
120435 |
120436 |
600258 |
600259 |
600678 |
158320 |
|
Causative gene |
MSH2 |
MLH1 |
PMS1 |
PMS2 |
GTBP |
MSH2/MLH1 |
*MTS = Muir-Torre syndrome
HNPCC is an autosomal dominant cancer predisposition characterised by colorectal adenocarcinoma (CRC) without (‘Lynch syndrome type 1’) or with (‘Lynch syndrome type 2’) extracolonic cancers including endometrium (EC), ovary (OC), stomach (SC), small bowel (SBC), hepatobiliary tract, ureter or renal pelvis, skin, pancreas, brain (glioblastoma) and others.
HNPCC is caused by inactivating mutations in genes of the DNA mismatch repair system (‘MMR’ genes). MMR gene mutations results in failure to repair errors during DNA replication. Cancer is likely to develop when unrepaired replication errors inactivate genes including tumour suppressors.
Muir-Torre syndrome (MTS) is an autosomal dominant disease defined by the coincidence of at least one sebaceous skin tumour and one internal malignancy, About half of MTS patients are affected by colorectal cancer. Mutations in MSH2 and MHL1 are associated with MTS.
Laboratory Analysis
Contact scientist: Ian Berry/Ruth Charlton
|
|
Test |
Target reporting time (working days) |
|
1. |
MSH2 sequence analysis of coding regions |
40 |
| 2. | MLH1 sequence analysis of coding regions | 40 |
| 3. | MLH1/MSH2 MLPA dosage analysis | 40 |
| 4. | MSH6 sequence analysis of coding regions | under development |
| 5. | PMS2 sequence analysis of coding regions | under development |
* Predictives = 10 working days to report
Tumour wax blocks can be sent for immunohistochemistry testing to check for loss of expression of MSH2 or MLH1.