- Hello!
I am a member of the GenomeConnect and ClinGen Patient Data Sharing Program team.
In this video, we will walk through an example genetic test report together.
We won t go through all of the terms you might see on your genetic test report in this video,
but please see our other videos for more information.
- Many of you listening have gone through the genetic testing process and might have
spoken to a genetic counselor or a geneticist, so some of what we review might be familiar.
Our hope is to break down some of the terms and information today.
- - On the screen here is an example report
we will be walking through.
This example report has a genetic change or variant called a single nucleotide variant.
A sequence variant means there is a change to a letter or a few letters within the DNA
sequence.
There are other types of genetic variants, which may be displayed differently on reports.
On this report, you can see there are many terms, like autosomal dominant, letters and
numbers to describe the variant, and words like heterozygous and de novo.
We will walk through each of these terms today and, as a reminder, you can learn more about
other terms that might be found on your report through our other videos.
- First, the report indicates which gene the genetic variant was found in.
You can see that this individual has a variant in the CHD8 gene.
Our genes provide instructions for proteins that tell our bodies how to grow, develop,
and function (similar to an instruction manual).
Each protein has a different role in the body.
- The next section is about any disease that is associated with the specific gene.
In this example, disease causing or pathogenic variants in the CHD8 gene have been associated
with Autism Spectrum Disorder.
It is important to remember, that not all variants in a gene cause disease and, sometimes,
even individuals with disease causing variants might not have the condition.
For clarification about your specific variant and diagnoses, talk to your doctor or genetic
counselor . -
- On this example report, there is a box that says Variant . This box tells us about the
specific change to the DNA sequence and the specific change to the protein that gene makes.
- First, we see a c. with letters and numbers.
The c. stands for coding which is how we know this is describing the DNA variant.
The number after c. 622 tell us there is a change at this specific location of the DNA
sequence.
The first letter is the nucleotide or DNA letter most people have at that position,
the greater than sign means it changed to the DNA letter after the that symbol.
In this specific example, the G>A tells us at this position, most people have a G while
this individual has an A. - Next, we see a p. with letters and numbers.
The p. stands for protein and the letters and numbers tell us the specific change to
that protein.
The letters are specific amnio acids.
The number 208 tells us there was a change in the amnio acid at position 208 in the protein.
The first word is the amnio acid most people have at that position in the protein.
The word after the number, is what that amnio acid was changed to.
In this example, Gly is an abbreviation for the amnio acid Glycine.
Glycine is the amnio acid typically in that position, in this individual it is replaced
with Serine (which is the amnio acid abbreviated Ser).
- Inheritance pattern refers to how the genetic condition is passed down in a family from
one generation to the next, Inheritance patterns are used to help us understand if one or two
disease causing or pathogenic variants are needed to cause a condition and whether the
gene is on the X-chromosome or Y-chromosome.
Inheritance patterns do not tell us if a genetic variant was inherited from a parent or whether
the variant was found on one or both copies of the gene.
Here you might see terms like autosomal dominant, autosomal recessive, or X-linked.
In this example report, we see autosomal dominant.
Autosomal means the gene is on one of the first 22 pairs of our chromosomes.
Individuals typically have two copies of these genes.
In this example report we see the inheritance pattern is autosomal dominant meaning this
individual has a disease causing or pathogenic variant on one copy of the gene, and may experience
signs or symptoms associated with the condition.
- Zygosity tells us more information about this specific individual who was tested and
their genetic variant, specifically if the variant was found on one copy of the gene
or both copies of the gene.
You may see heterozygous, homozygous, or hemizygous in this box to help describe this.
In this example report we see the zygosity is heterozygous meaning this individual has
the variant on one copy of the gene.
- Testing parents can help us understand if a genetic variant was passed from a biological
parent to the child or if the genetic variant is new in the child.
In this example report we see the inherited from is de novo meaning this was a new variant
in the child.
- Classification is the laboratory s interpretation of the genetic variant and its relationship
to health and disease.
The classification takes many things into account about the specific variant and is
based on the information at the time the variant was reported.
Some variants impact our health and others do not.
There are three main buckets for classification: benign/likely benign, variant of uncertain
significance, pathogenic/likely pathogenic.
Benign means that the copy number or sequence variant is not thought to impact gene function
and independently cause any significant health or developmental differences.
Pathogenic means the variant is thought to impact gene function and contribute to disease.
A pathogenic variant could explain a person s symptoms, increase an individual s chance
to develop a certain condition, or increase the chance of having a child with a certain
condition.
Finally, VUS means there is not enough evidence to say that a variant is associated with health
or developmental differences.
More information is needed.
We see this example s variant was classified by the laboratory as variant of uncertain
significance meaning it has an uncertain or unclear impact on health
- For additional information about specific terms you have heard on this video or for
more information about other terms on your or your family member s genetic test report,
please watch our other videos.
- Thank you for watching our XXX video!
If you have general questions about XXX or other genetics-related topics, you can reach
us at info@genomeconnect.org or by calling 570-214-1721 or toll free 855-322-7683
- If you have questions about your genetic test results, we encourage you to reach out
to your doctor or genetic counselor.
- We hope you join us for our other videos!