Testing For Cancer Genes – What Are the Implications For Patients and Relatives?

Researchers have made enormous progress in finding the genes – the inherited codes of instructions that control the body’s development – that code for several cancers. One of the breast cancer genes, BRCA1 (Breast Cancer) was identified in 1994. genee

What is a gene?

* A gene is made up of a long string of four different chemicals (called bases) represented by the letters C, G, A and T, arranged in a specific and unique sequence. A section of a gene might read: CGGATCCTA
* The BRCA1 gene contains 100,000 of these letters and a faulty gene is created by the alteration of one or more of these letters, at any position in the line. A faulty section of the gene shown above might read: AGGATCCTA

To identify a faulty BRCA1 gene in a particular family, we take a blood sample from someone with breast or ovarian cancer in the family, extract the genetic material – the DNA – and then work our way along the BRCA1 gene sequence until we identify the faulty section. In most cases, we cannot do a genetic test on anyone else in the family until we have identified the faulty gene in someone with breast or ovarian cancer in that family.

Testing is a two-step process:

1. identify the faulty gene in a particular family, and then

2. offer genetic testing to other members of that family who have not yet developed cancer.

Many cancer genetic centres are now offering to search for faulty BRCA1 genes, testing unaffected individuals related to someone who has suffered breast cancer. This is also underway for ovarian cancer and colorectal cancer.

I believe that identifying a cancer gene may cause distress to some people, particularly in some young women with breast cancer. Other people seem to suffer no psychological damage at all on being told that they have a cancer gene.
What are the issues facing people without cancer who are offered testing for cancer genes?

It is essential to remember that testing is a completely personal decision for each individual. If you – or a member of your family – are offered testing you must be absolutely certain that you understand fully: all the options available, with the advantages and disadvantages of each available option; the information a genetic test will give you; the foreseeable consequences of having a genetic test; and areas where the likely consequences of having a genetic test are hard to predict.

One of the questions that I am often asked, falling into the last category, is ‘How will having a genetic test affect my insurance position?’. This is a complicated issue which may well become clearer over the next few months.

The Human Genetics Advisory Commission issued a report on these matters in December 1997, which was followed by a Department of Health response issued in November 1998. There has been no response to either of these documents from the Association of British Insurers – a group including the majority of insurance companies in the United Kingdom but without any regulatory or mandatory power. stylowakobieta

The Human Genetics Advisory Commission made three clear recommendations:

* that insurance companies should not have access to genetic information until an independent professional body has satisfied itself that the test is valid, and that the information derived from that test is accurately interpreted;
* that an independent appeals mechanism be established, and given appropriate regulatory powers;
* that there be a 2 year moratorium (a period of reflection and discussion) extending from December 1997.



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