Cancer genes – examples:
Breast cancer: We screen for 15 different breast cancer genes, alterations in which put patients at up to 2-8 times the normal population risk. If you have an alteration in such genes, the age of starting breast screening and its frequency would be adjusted. This will enable earlier diagnosis and potentially reduce the risk of dying from breast cancer.
For those at the very highest risk of genetically-defined breast cancer, women can consider lifesaving skin sparing mastectomy with aesthetic combined reconstruction surgery, or more intensive screening.
Alterations in the BRCA1 and BRCA2 genes increase the risk of breast cancer, but they also increase the risk of ovarian cancer. With this knowledge, women can choose to have their ovaries and fallopian tubes removed, after childbearing years, as a life saving measure.
Men who inherit alterations in BRCA1 or BRCA2 may also be at risk of male breast cancer or prostate cancer, and would be similarly provided with advice for risk management.
Ovarian cancer: we test for alterations in 9 genes including BRCA1 and BRCA2.
Colon cancer: If an alteration in a colon cancer risk gene is found to be present, lifesaving regular colonoscopy screening can be started as early as 25-30 years of age, depending on the specific alteration. Almost all colon cancer starts with a pre-cancerous phase of colonic polyps which gradually increase in size before becoming cancerous. These polyps can be detected at colonoscopy and simply removed at the same time. Regular colonoscopies every 1-5 years can result in 70 per cent of colon cancers being prevented.
Prostate cancer genes: – Prostate cancer screening is currently controversial in the general population. Prof Eeles has recently published data to show that men who carry alterations in the cancer predisposition gene, BRCA2, should be offered regular prostate screening using the PSA blood test.
We are screening for a large number of actionable Cardiac genes combined with an onsite Echocardiogram – a sophisticated non-invasive way of filming the heart in action. This is a key reason why The London Genetics Centre was the correct place for this study.
Cardiomyopathies– are heart muscle disorders that are not due to coronary artery disease. Genes control heart muscle development; gene alterations can cause two of the most common types of heart muscle disorder:
1) Dilated cardiomyopathy – the heart being a floppy enlarged bag.
2) Hypertrophic cardiomyopathy – the heart muscle becomes excessively thick. Some people carry certain cardiomyopathy gene alterations without developing signs or symptoms of cardiomyopathy. We are doing an Echocardiogram in all patients before the gene test which means we can tell such a patient that while they have a genetic alteration that can cause cardiomyopathy their heart Echo is normal and they do not have any evidence of the condition. We would however, occasionally repeat the Echo to check there is not any change over the years.
However, if their echocardiogram shows early signs of cardiomyopathy, knowing they have such a gene alteration means a patient can start lifesaving drugs, or treatments earlier, making an enormous difference.
Long QT genes – Inherited alterations in these genes can cause life threatening heart rhythm disorders; having the knowledge of such gene alterations being present can be lifesaving. Lifestyle advice includes avoiding certain medicines known to prolong the QT interval.
Aortopathy genes – Alterations in these genes can result in an enlarging and weakening of the aorta – the main artery that comes off the heart. Ultrasound screening for these aneurysms can identify if/when radiological or surgical procedures are needed.
Familial Hypercholesterolaemia – alterations in these genes result in dramatically high cholesterol levels. This can be treated with diet and medications, which significantly lower the risk of heart attacks and strokes.
Actionable “non-oncological/non-cardiological genes”: a few examples:
Factor V Leiden – Deep vein thrombosis is increased 8 times by the presence of this genetic alteration, which can cause fatal pulmonary embolism (clots in the lungs). Prevention involves using anticoagulants when at risk, such as flying or post-surgery. Also we advise against the combined contraceptive pill, as the risk of clots is increased many times if this alteration is present.
Haemochromatosis – an iron overload genetic alteration causes increased absorption of iron which can result in fatal liver, pancreatic and cardiac damage. This can be easily treated by intermittently removing some blood, to stop the iron build up and its toxic effect.