SickKids Cancer Sequencing Program
During the consent discussion, we will ask your permission to access different sample types - both tumour and germline. Many of these samples are collected from procedures that are clinically indicated (meaning recommended by you/your child’s healthcare team), and we do not collect every sample type from each participant. The additional sample types that we may ask to collect are: blood, saliva, and skin (from a small biopsy). You/your child will have the opportunity to decline the collection of any sample.
There are three types of genetic tests that we may perform on tumour and germline samples: cancer panel, whole genome sequencing (WGS), and RNA sequencing (RNA-Seq). Each is described in further detail below.
Cancer panel: The term “panel” refers to a collection of genes that are all associated with a particular medical condition. For example, there are genetic testing panels that are designed to look for pathogenic variants (or “mutations”) in genes associated with breast cancer. Panels vary in size, from two genes to hundreds of genes. The KiCS cancer panel includes genes that are associated with many different types of cancer. Our panel reads the spelling of (or “sequences”) over 800 genes!
WGS: Not all of our genetic material, or “genome”, codes for proteins. In fact, the coding region of our genome (or “exome”) accounts for only 1% of our genome (for more information about the exome please click here). There are regions between the coding sequences that can tell us more about a person’s cancer, or susceptibility to developing cancer. WGS reads the spelling of the entire genome, including coding and non-coding areas.
RNA-Seq: RNA carries our genetic instructions like a messenger, from DNA to the machinery in our cells that makes proteins. Sometimes, regions of our RNA can swap, or fuse together, leading to a protein that may not work properly. By studying RNA, we can detect these fusions, and learn more about genetic changes that may influence our susceptibility to cancer, or therapeutic options.
Since this is a research program, we are unable to provide an expected date that clinical teams and families should expect to receive results. The three genetic analyses are performed at staggered times, as the testing and interpretation processes are quite different. The first test that we perform on tumour and germline samples is the cancer panel. If there are genetic changes identified in this test that may impact care, these results are typically returned approximately three months after enrolment. If you are wondering about the status of your/your child’s sample, please email firstname.lastname@example.org.
Germline: Pathogenic variants (or “mutations”) in genes associated with cancer will be returned, either by your/your child’s oncology team or by a genetic counsellor. We will also return results if a mutation is identified in a gene associated with a “medically-actionable” condition (a medical condition for which there is a cure, prevention, or treatment), and refer you/your child to the appropriate medical specialists.
Tumour: Genetic changes that may impact your/your child’s treatment will be returned by the oncology team.
We all have many genetic changes or “variants”. Some of these variants are harmful or “pathogenic”, meaning that they cause the gene to stop working properly and may lead to medical conditions. Some variants are harmless or “benign”. These are the genetic changes that make us different from one another, and do not cause health concerns. There are other variants for which we do not have enough evidence to call benign or pathogenic. These variants are classified as “variants of uncertain significance” or “VUS”. While we may not have enough evidence today to understand the effect of a VUS, we may be able to call it “pathogenic” or “benign” in the future.
The KiCS Program does not return benign variants or VUS. We also do not return pathogenic variants in genes associated with “not medically-actionable” conditions (medical conditions for which there is no cure, prevention, or treatment at this time).
The KiCS Program does not return carrier status. Some genetic conditions are caused when a person inherits a mutation from both parents. When a mutation is inherited only from one parent, the individual does not develop the medical condition, but is considered a “carrier”. Since being a carrier does not impact you/your child’s current health, we do not return this result.
The KiCS Program does not return your/your child’s “raw genetic data”. This term refers to the large electronic file that contains the spelling of your/your child’s DNA or RNA letter by letter.
The KiCS program is a research study that aims to identify genetic changes that will provide further information about your/your child’s cancer diagnosis (or suspected predisposition to cancer). This program does not aim to identify every pathogenic variant in your/your child’s genome, and should not be relied upon to discover your/your child’s risk for all genetic conditions.
If you have a family history of a medical condition that you are suspicious may be due to an inherited genetic mutation, we encourage you to discuss a referral to a genetics clinic with your family doctor.
If you or your family have additional questions about participation in the KiCS Program, or would like clarification about the information reviewed above, please email email@example.com.