With the new day comes new strength and new thoughts

- Eleanor Roosevelt

Cancer and genetics

All cancers develop because something has gone wrong with one or more of the genes in a cell. A change in a gene is called a ‘fault ‘or ‘mutation’. Some people may have an increased risk of particular types of cancer because they have an inherited gene fault.

Inherited cancer genes occur when there is a mistake or fault in the genes in an egg or sperm cell. These cancer genes can be passed on from parent to child and can increase the risk of cancer developing. Genes that increase the risk of cancer are called cancer susceptibility genes.

However, just because you have an inherited predisposition to cancer, does not necessarily mean you will definitely get it. For a cancer to develop, several different gene mutations would need to occur.

Factors such as a strong family history of cancer and at a young age , can be a strong indicator of whether or not you should consider being tested for an inherited gene fault.

If you suspect that you may have an inherited gene fault, there are measures than can be taken. There are tests available to test for genetic markers of gene faults, however this can come with its own set of issues.


For more information on symptoms and diagnosis of cancer, visit: https://www.mariekeating.ie/cancer-information/

Advantaged of genetic testing-

  • If your tests come back negative, you can still make changes in lifestyle to reduce your risk of developing cancer in the future.
  • If tests come back positive, you know what the consequences of this could be and you can make an informed, educated decision on how you would manage this to move forward.
  • In some cases, there are medications or preventative surgeries that can be taken to drastically reduce your chances of developing your inherited form of cancer. This would need to be discussed with a health professional.

Things to consider before getting tested:

  • Are you prepared for your results?
  • Would you rather not know if you were to receive bad news?
  • If treatment is and option, would you consider it?

Tests for Genetic Cancers:

Thankfully, many genetic cancers can be tested for to reveal whether or not you have predisposition to a familial strain of cancer. Some of these tests include BRCA 1 and BRCA 2.

Visit the BRCA section of the Marie Keating website for more information.

Bowel Cancer Tests-

  • Familial adenomatous polyposis (FAP) – FAP is caused by a fault in the APC gene. A faulty APC gene can cause hundreds of non-cancerous (benign) growths called polyps to develop in the bowel at a young age. If left untreated, all people with this syndrome will almost certainly develop bowel cancer by their 40s.
  • Lynch syndrome- Lynch syndrome is also called hereditary nonpolyposis colon cancer (HNPCC). It is caused by faults in the MLH1, MSH2, MSH6 and PMS2 genes. Between 70 and 90 out of 100 people with Lynch syndrome (70 to 90%) develop bowel cancer. Most of the bowel cancers occur under the age of 50. People with Lynch syndrome also have an increased risk of developing other cancers including womb and ovarian cancer in women.

Breast Cancer Tests-

  • BRCA1 and BRCA2 genes – Faulty BRCA1 and BRCA2 genes are rare. Specialists estimate that around 7 in 10 women (70%) with faults in either BRCA gene will develop breast cancer by the age of 80. These genes also increase the risk of ovarian cancer and BRCA2 increases the risk of male breast cancer and prostate cancer
  • TP53 and PTEN – The TP53 gene normally controls when a cell divides. It is a type of tumour suppressor gene. It causes breast cancer as part of a rare cancer syndrome called Li Fraumeni syndrome. PTEN is the gene fault that causes a rare condition called Cowden syndrome and increases the risk of breast cancer

Kidney Cancer Tests-

  • Birt Hogg Dube syndrome (BHDS) – Birt Hogg Dube syndrome (also known as BHDS) is caused by faults in the FLCN gene (also known as BHD). People with BHDS develop multiple benign skin tumours (fibrofolliculomas) on the face, neck and upper body. People with BHDS are at increased risk of kidney cancer.
  • Von Hippel Lindau (VHL) syndrome – Von Hippel Lindau syndrome is a rare inherited condition caused by faults in the VHL gene. Kidney cysts are common in VHL syndrome. These cysts do not usually affect how the kidney works, but sometimes a type of kidney cancer called clear cell renal cell cancer (CCRCC) can develop in a cyst.


  • Familial atypical multiple mole melanoma syndrome (FAMMM)– Researchers have found that familial atypical multiple mole melanoma syndrome (FAMMM) increases the risk of developing melanoma. People who have FAMMM have more than 50 moles and at least one close relative has been diagnosed with a melanoma.

Ovarian Cancer-

  • BRCA genes – As well as causing breast cancer, a fault in the BRCA genes can also lead to an increased susceptibility to developing ovarian cancer/ 5 to 15 out of every 100 (5 to 15%) of women with ovarian cancer have a faulty gene. In most cases, they will have either a faulty BRCA1 or BRCA2 gene. A BRCA2 gene fault also increases the risk of breast cancer in men and prostate cancer.
  • Lynch syndrome (HNPCC) – Lynch syndrome is also called HNPCC (hereditary nonpolyposis colorectal cancer). Lynch syndrome is more commonly linked to bowel cancer but can also increase the risk of ovarian cancer.  Between 10 and 12 out of 100 women (10 to 12%) with Lynch syndrome will develop ovarian cancer. Researchers think that around 2 out of every 100 ovarian cancers diagnosed (2%) are linked to Lynch syndrome.

Pancreatic Cancer-

  • Peutz Jeghers syndrome (PJS) – PJS is linked to a gene fault called STK11. Peutz Jeghers syndrome increases the risk of bowel cancer as well as other types of cancer. If someone has PJS, the skin around the mouth, nostrils, eyes, and near the back passage may be darker than surrounding skin.


Many thanks to Cancer Research UK for testing information
and for more  on genetic testing visit: https://tinyurl.com/y4u5lbku.