Sometimes we suspect a medical condition is due to a change in one specific gene. If that’s the case, we can test just that particular gene. This is called single gene analysis. In this section, we explain how single gene analysis works and the different types of results.
Sometimes we suspect a medical condition is due to a change in one specific gene. If that’s the case, we can test just that particular gene. This is called single gene analysis. This process checks for any spelling errors, or mutations, only in that single gene.
After the gene is analyzed, we will be able to tell if there are any DNA sequence variants. We can then try to determine what sort of effect, if any, each variant has on the gene’s function.
For example, is the variant significant enough that it will cause disease? Is the variant neutral or mild enough that it doesn’t really impact the way the body functions?
Single gene analysis can have several different results.
A positive result means that a genetic test identified a change in a gene that we are confident causes the features in you or your child. Another word that you may see on a report to describe a positive result is “pathogenic”.
A likely positive result means that a genetic test identified a change in a gene that is suspected to cause the clinical findings in you or your child, but there may not be enough scientific information known at this time to say it is definitively positive.
A negative result means that there were no gene changes identified by the testing method that could explain your or your child’s clinical findings.
A variant of unknown clinical significance is a genetic change that, based on the currently available scientific knowledge, cannot be interpreted as pathogenic or negative.
In the future, scientists are likely to discover what these variants of unknown clinical significance mean. Until then, receiving results with a variant of unknown clinical significance can be understandably frustrating as we can’t interpret what the DNA change means for your child or family.
Keep in mind, genetic testing does not always find an explanation for medical symptoms.
The absence of a positive genetic testing result does not take away an individual’s clinical diagnosis.
Also, a non-diagnostic genetic testing result does not mean that the condition is not genetic. Instead it may mean that the testing completed was not able to identify a genetic cause at this time.*