What is Lynch Syndrome: (Thanks to Sir John Burn... - OvaCare


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What is Lynch Syndrome

(Thanks to Sir John Burn Lynch Syndrome UK Conference 2015)

We all inherit our DNA 50% from each parent. If we have LS then one of our repair genes is good while the other one is faulty.

Think of the repair genes as two Doormen on the door at a night club. Nothing is going to get past them that shouldn’t. This is a person without LS

Imagine one of the Doormen needs the toilet and walks off. We still have one doorman watching and keeping us safe. This is a person with LS

Imagine the other doorman now needs to toilet and leaves. Nobody is now watching door. This is what happens when one good gene goes faulty for what ever reason. Anybody can just walk in now

In brief, we only have one repair gene looking out for us and if it gets damaged in a cell we are left with no protection.

5 Replies

How do you know if your Ovarian Cancer is connected to Lynch Syndrome, could you expand and let us know what tests etc please

in reply to

Like hereditary breast and ovarian cancer syndrome, caused by mutations in the BRCA1 and BRCA2 genes, Lynch syndrome is caused by mutations in 5 different genes (MLH1, MSH2, MSH6, PMS2, EPCAM).

These genes are involved in the repair of mistakes that occur when DNA is copied in preparation for cell division (a process called DNA replication). Mutations in any of these genes prevent the proper repair of DNA replication mistakes. As the abnormal cells continue to divide, the accumulated mistakes can lead to uncontrolled cell growth and possibly cancer

Although mutations in these genes predispose individuals to cancer, not all people who carry these mutations develop cancerous tumours.

In addition to an increased risk of colorectal cancer, individuals with Lynch syndrome are also at an increased risk for cancers of the:




Small intestine

Plus a number of other areas.

What are some red flags for Lynch syndrome?

1. Three or more closely related family members with colorectal, endometrial, or other Lynch-associated cancer (mentioned above).

2. Cancer diagnoses in two or more generations.

3. A family member diagnosed with colorectal or endometrial cancer before the age of 50.

These features are often referred to as the Amsterdam criteria. However, not all families that meet the Amsterdam criteria have Lynch syndrome.

A family member with cancer gives their consent to have their tumour tested. Based on this result, they may be offered genetic testing to find the fault on the gene.

If a fault is found in that family member, then genetic testing can be offered to other members of the family. It is up to each family member to decide if they wish to be tested or not.

We do not know how many people in Ireland are affected(we estimate aprox. 15,000 people) but we are reasonably sure that it is largely undiagnosed.

If you have been diagnosed with Lynch Syndrome regular screening will be advised.

Main screenings:

Colon (large bowel)

Womb and Ovaries

(Some women with a high risk of getting cancer and who have completed their families can decide to have risk-reducing surgery. This involves removing the womb and ovaries)

Stomach screening.

Hope this is of some help.

in reply to

Since diagnosis I have had one cousin die of pancreatic cancer and her sister had breast Cancer, A first cousin on the same side also had breast Cancer but neither will say anything apart from Braca test is the way to go. I did bring this up at a Patient day in Ovacare and the consultant mentioned Lynchs and suggested I have Braca testing. I expect to have this done in the not so distant future/

in reply to

The first thing to do is to talk to your GP and if necessary they can arrange a referral to a geneticist. During your first meeting they will talk you through your family history and will make a recommendation based on this in relation to testing. Recently I had a cousin who had a strong family history of cancer and she was initially tested for the BRCA genetic defect(because she previously had breast cancer) and when this proved negative they then did some more genetic testing....again this turned out to be negative.

Best of luck in whatever you decide.

Remember knowledge is power.

in reply to

Ovarian Cancer Uk: Lynch syndrome (LS) is a condition that can run in families. It doesn’t cause any symptoms, but people with LS have an increased risk of developing several types of cancer, including bowel & ovarian cancer > ow.ly/y0BW30kTYND

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