concerning genetic analysis for hereditary cancer

Introduction

You have been referred to genetic counselling as hereditary cancer is suspected in yourself and/or in your family. For this reason, you have been offered a genetic analysis. This information is a short description of the genetic analysis and how the result can affect you and your family.  You are always welcome to contact your genetic counsellor or the physician responsible for your course of treatment at the Department of Clinical Genetics if you have any further questions.

Genetic analysis

We will examine and analyze a part of your genetic material (genes) from a blood sample. Humans have approximately 20,000 genes, and the genetic analysis that you are offered includes approximately 40 genes. All these genes are associated with an increased risk of cancer if one or more pathogenic variants (mutations) are detected.  Not all the genes that will be analyzed, are related to the specific type(s) of cancer that you and/or your family have experienced. Consequently, you need to be aware that we in rare cases detect a pathogenic variant in a gene, that was not expected. However, if a pathogenic variant is detected we will offer counselling and a surveillance program depending on e.g., your age and sex.

If a pathogenic variant is detected

In most cases the result of the genetic analysis will be normal.  If one or more pathogenic variants of clinical significance are detected, you will be informed by your physician/ genetic counsellor and offered a follow-up consultation with a physician. At this consultation you will be informed in more detail about the pathogenic variant that has been detected, how it is inherited and whether you will be offered a surveillance program. In some cases, it will be possible to test your family members, and a plan will be made at the consultation regarding how to inform them.

In some cases, a single genetic variant may be detected in a gene where two genetic variants are required to develop the disease (known as autosomal recessive inheritance). If such a variant is detected, you are a healthy carrier. Detecting such a variant has no impact on your health. The risk that your children or other family members would inherit two variants — and thereby develop the disease — is very low unless you have or plan to have children with a close relative, such as a cousin. Since no further action is needed if such a variant is detected, you will not always be informed, but it will usually be recorded in your medical record.

Variants of unknown significance

In many cases, when performing a genetic analysis, one or more “variants of unknown significance” are detected. It can be difficult to determine if such a variant has a health-related impact or if it simply is a rare normal variant. In most cases, there is no reason for concern or need for further analysis. It will not necessarily be stated in your medical record if a rare variant of unknown significance has been detected. In some cases, additional laboratory analysis and blood samples may be necessary to evaluate whether the variant has an impact on your health. If such analysis is relevant, you will be informed by your physician/genetic counsellor.

Will I be able to access the result of my genetic analysis?

In some cases, it will be possible to access the result of the genetic analysis via “minSP” or Sundhed.dk. It can be difficult to understand and interpret the results of genetic analysis. In the laboratory, the result from the genetic analyses is carefully evaluated with different methods such as computer programs. It can cause unnecessary concern if you access your own results, especially if a variant of unknown significance is detected (as described above). If a variant of unknown significance is detected and further analysis is relevant, you will be informed by your physician/genetic counsellor.