As the utility of genetic testing in pediatric neurology is expanding, so are the testing options. It can be challenging to determine which test is the most appropriate. Clinicians can order genetic tests that assess a single gene, a small panel of genes, or the entire genome. Further adding to the complexity, each test uses different methodologies, each of which can detect only certain types of variants. Identifying which test is right for a specific situation involves collaborating with patients, families, and genetic experts to evaluate the potential value of a molecular diagnosis, the benefits and limitations of genetic testing, and relevant factors in genomic test selection.

This module will provide an overview of the issues clinicians should consider when deciding whether to offer neurogenetic testing and choosing among the available tests.

In these cases, you will practice:

• Identifying clinical situations for which there is further value added by molecular diagnosis
• Evaluating the appropriateness of different genetic tests in specific clinical contexts
• Evaluating when consulting a genetic expert can be helpful

Genetic testing in pediatric neurology can provide valuable information for diagnosis and treatment. Genetic tests with a larger scope, including exome testing, have benefits and limitations which include:

• Greater potential yield for identifying a causative variant.
• Increased likelihood of identifying uncertain or secondary findings.
• Lower sensitivity for certain types of variants, including deletions/duplications and trinucleotide repeats.

Other considerations for genetic testing

• Genetic test methodologies differ in the types of variants they can detect.
• Thoughtful test selection is required because of the variability in what labs offer, including the ability to detect a specific condition. 
• There are options for people who have had inconclusive genomic testing previously because testing evolves.
• Collaborating with a genetic expert is important due to the complexity of genetic testing.
• Facilitating shared decision-making with the family helps determine the test characteristics that best fit the family's needs and perspectives.

Visit Dig Deeper for a more detailed discussion of:

• Considerations in choosing a genetic test
• Exome vs. whole genome sequencing
• Targeting treatment using genomics
• Trio testing in exome testing
• Variants of uncertain significance

Visit Tools for clinical resources on:

• Finding genetic experts
• Talking with patients: pretest counseling, exome testing, and patient materials
• Patient reactions to genetic testing results
• Genetic testing methods
• Variant reclassification
• Interpreting genomic reports